Syrian gunners pounded an opposition stronghold where the last dispatches from a veteran American-born war correspondent chronicled the suffering of civilians caught in the relentless shelling. An intense morning barrage killed her and a French photojournalist -- two of 74 deaths reported Wednesday in Syria.

"I watched a little baby die today," Marie Colvin told the BBC from the embattled city of Homs on Tuesday in one of her final reports.

"Absolutely horrific, a 2-year old child had been hit," added Colvin, who worked for Britain‘s Sunday Times. "They stripped it and found the shrapnel had gone into the left chest and the doctor said, ’I can‘t do anything.’ His little tummy just kept heaving until he died."

Colvin and photographer Remi Ochlik were among a group of journalists who had crossed into Syria and were sharing accommodations with activists, raising speculation that government forces targeted the makeshift media center, although opposition groups had previously described the shelling as indiscriminate. At least two other Western journalists were wounded.

Hundreds of people have died in weeks of siege-style attacks on Homs that have come to symbolize the desperation and defiance of the nearly year-old uprising against President Bashar Assad.

The Syrian military appears to be stepping up assaults to block the opposition from gaining further ground and political credibility with the West and Arab allies. On Wednesday, helicopter gunships reportedly strafed mountain villages that shelter the rebel Free Syrian Army, and soldiers staged door-to-door raids in Damascus, among other attacks.

The bloodshed and crackdowns brought some of the most galvanizing calls for the end of Assad‘s rule.

"That’s enough now. The regime must go," said French President Nicolas Sarkozy after his government confirmed the deaths of Colvin, 56, and Ochlik, 28.

The U.S. and other countries have begun to cautiously examine possible military aid to the rebels. U.S. Secretary of State Hillary Rodham Clinton heads to Tunisia for a meeting Friday of more than 70 nations to look at ways to assist Assad‘s opponents, which now include hundreds of defected military officers and soldiers.

"This tragic incident is another example of the shameless brutality of the Assad regime,’‘ U.S. State Department spokeswoman Victoria Nuland said of the killing of the journalists.

In Saudi Arabia, the state news agency described King Abdullah scolding Russian President Dmitry Medvedev -- one of Assad’s few remaining allies -- for joining China in vetoing a U.N. Security Council resolution this month condemning the violence.

But even Moscow said the ongoing bloodshed adds urgency for a cease-fire to allow talks between his regime and opponents.

Washington had strongly opposed arming anti-Assad forces, fearing it could bring Syria into a full-scale civil war. Yet the mounting civilian death tolls -- activists reported at least 74 across Syria on Wednesday -- has brought small but potentially significant shifts in U.S. strategies. It remains unclear, however, what kind of direct assistance the U.S. would be willing to provide.

The toppling of Assad also could mark a major blow to Iran, which depends on Damascus as its main Arab ally and a pathway to aid Iran‘s proxy Hezbollah in Lebanon.

"We don’t want to take actions that would contribute to the further militarization of Syria because that could take the country down a dangerous path," White House press secretary Jay Carney said. "But we don‘t rule out additional measures if the international community should wait too long and not take the kind of action that needs to be taken.’‘

The U.N. estimates that 5,400 people have been killed in repression by the Assad regime against a popular uprising that began 11 months ago. That figure was given in January and has not been updated. Syrian activists put the death toll at more than 7,300. Overall figures cannot be independently confirmed because Syria keeps tight control on the media.

On Wednesday, the U.N. said that Secretary-General Ban Ki-moon would dispatch Valerie Amos, the undersecretary-general for humanitarian affairs, to Syria to assess the situation. No date was set.

Twenty of the deaths reported Wednesday were in Homs, where resistance forces include breakaway soldiers. Homs has drawn comparisons to the Libyan city of Misrata, which withstood withering attacks last year by troops loyal to Moammar Gadhafi.

"It is a city of the cold and hungry, echoing to exploding shells and burst of gunfire,’‘ Colvin wrote in what would be her last story published Feb. 19. "There are no telephones and the electricity has been cut off. Few homes have diesel for the tin stoves they rely on for heat in the coldest winter that anyone can remember.’‘

She described shrinking supplies of rice, tea and cans of tuna "delivered by a local sheik who looted them from a bombed-out supermarket.’‘

"On the lips of everyone was the question, `Why have we been abandoned by the world?’" she wrote.

Syrian activists said at least two other Western journalists -- French reporter Edith Bouvier of Le Figaro and British photographer Paul Conroy of the Sunday Times -- were wounded in Wednesday‘s shelling.

Amateur video posted online shows the two injured journalists in a makeshift clinic. The French journalist, Bouvier had her left leg tied from the thigh down in a cast. A doctor in the video explains that she needs emergency medical care. Conroy appears in the video and the doctors say he has deep gashes in his left leg.

In one tragic image, a man with a bandaged head is shown mourning his son, who was purportedly killed by government shelling in Homs on Saturday. The video was released by activists Wednesday and the details could not be confirmed. Colvin described seeing a 2-year-old child killed Tuesday and it did not appear to be related to that video.

A Homs-based activist, Omar Shaker, said the journalists were killed when several rockets hit a garden of a house used by activists and journalists in the besieged neighborhood of Baba Amr. Shaker said tanks and artillery began intensely shelling at 6:30 a.m. and was continuing hours later. He said the room used by journalists was hit around 10 a.m.

Amateur video posted online by activist showed what they claimed were bodies of the two journalists in the middle of a heavily damaged house. It said they were of the journalists. One of the dead was wearing what appeared to be a flak jacket.

The intense shelling in parts of Homs -- with blasts occurring sometimes just a few seconds apart -- appeared to have had no clear pattern over the past week, hitting homes and streets randomly. Some have suggested that the house used by the journalists and activists was pinpointed by Syrian gunners, perhaps by following the signals from satellite phones and other communication equipment.

The French culture minister, Frederic Mitterrand, claimed the journalists were "pursued’‘ as they tried to find cover but he did not elaborate. A campaigner for online global activist group Avaaz, Alice Jay, said the group was "directly targeted.’‘

Another Avaaz activist, Alex Renton, alleged that seven Syrians trying to reach Baba Amr with medical supplies and a respirator were found shot to death with their hands tied behind their back. Two other activists, including a foreign paramedic, traveling with the seven are missing, he added. The claims could not be immediately confirmed.

Many foreign journalists have been sneaking into Syria illegally in the past months with the help of smugglers from Lebanon and Turkey. Although the Syrian government has allowed some journalists into the country their movement is tightly controlled by Information Ministry minders.

Colvin, of East Norwich, N.Y., was a veteran foreign correspondent for the Sunday Times for the past two decades. She was instantly recognizable for an eye patch worn after being wounded covering conflicts in Sri Lanka in 2001.

Colvin said she would not "hang up my flak jacket’‘ even after that injury.

"So, was I stupid? Stupid I would feel writing a column about the dinner party I went to last night,’‘ she wrote after the attack. "Equally, I’d rather be in that middle ground between a desk job and getting shot, no offense to desk jobs

Ochlik, who had set up a photo agency IP3 Press, won first prize in the general news category of the prestigious 2012 World Press Photo contest for his 12-photograph series titled "Battle For Libya."

"I just arrived in Homs, it‘s dark,’‘ Ochlik wrote to Paris Match correspondent Alfred de Montesquiou on Tuesday. "The situation seems very tense and desperate. The Syrian army is sending in reinforcements now and the situation is going to get worse -- from what the rebels tell us.’‘

"Tomorrow, I’m going to start doing pictures," he added.

The New York-based Committee to Protect Journalists condemned the killings of the journalists, calling them an "unacceptable escalation in the price that local and international journalists are being forced to pay" in Syria.

A statement by Information Minister Adnan Mahmoud said there was "no information" about Colvin, Ochlik and other foreign journalists in Syria who entered without official permission, the state-run news agency SANA reported. It warned all foreign journalists to come forward to "regularize their status."

In London, British diplomats summoned Syria‘s ambassador to the Foreign and Commonwealth Office, asking Syrian officials to facilitate immediate arrangements for the repatriation of the journalists’ bodies and for help with the medical treatment of the British journalist injured in the attack.

The Britain-based Syrian Observatory for Human Rights said it had no information that the bodies of the two slain journalists had been carried out of Homs.

On Tuesday, a Syrian sniper killed Rami al-Sayyed, a prominent activist in Baba Amr who was famous for posting online videos from Homs, colleagues said.

On Jan. 11, award-winning French TV reporter Gilles Jacquier was killed in Homs. The 43-year-old correspondent for France-2 Television was the first Western journalist to die since the uprising began in March. Syrian authorities have said he was killed in a grenade attack carried out by opposition forces -- a claim questioned by the French government, human rights groups and the Syrian opposition.

Last week, New York Times correspondent Anthony Shadid died of an apparent asthma attack in Syria after he sneaked in to cover the conflict.

Elsewhere in Syria, the military intensified attacks.

In the northwestern province of Idlib, a main base of the Free Syrian Army, the Syrian Observatory for Human Rights claimed that Syrian military helicopters fitted with machine guns strafed the village of Ifis. Syrian combat helicopters are primarily Russian-made, though they also have a number of French choppers.

Another opposition group, the Local Coordination Committees, said troops conducted raids in the Damascus district of Mazzeh district and the suburb of Jobar, where dozens of people were detained. In Jobar, the group said troops broke down doors of homes and shops and set up checkpoints.

The group also said troops backed by tanks stormed the southern village of Hirak and conducted a wave of arrests.

In the Gulf nation of Bahrain, some anti-Assad protesters at a Syria-Bahrain Olympic qualifying football match waved the rebel flag and threw shoes at a small group of pro-regime supporters. (AP)