BEIRUT (AP) ― Syrian government warplanes carried out air strikes on a rebellious neighborhood in the capital and a village in the country’s northeast on Sunday, killing at least 25 people, including a dozen children, activists said. 

With its ground forces stretched thin, President Bashar Assad’s regime has relied heavily on its fighter jets and helicopters to try to stem rebel advances in the country’s civil war. The air raids frequently hit civilian areas, drawing criticism from the international community.

A Human Rights Watch report last week accused the Syrian government of committing war crimes by using indiscriminate and sometimes deliberate air strikes against civilians, killing at least 4,300 people since the summer.

On Sunday, a government jet bombed rebel-held areas in the predominantly Kurdish village of Hadad in the northeastern province of Hassaka, according to the Britain-based Syrian Observatory for Human Rights. It said at least 16 people were killed, including two women and three children.

A Hassaka-based activist who was in Hadad when the plane struck said the bombs sent huge plumes of black smoke billowing over the town. He spoke on condition that he be identified only by his nickname of Abu Qasem ― by which he is widely known among his comrades ― out of fear of reprisals.

Another air strike on the Damascus neighborhood of Qaboun killed at least nine children, the Observatory said.

The government frequently targets Qaboun, where rebels pushed into early this year. The district has been ravaged by heavy street clashes and shelling since then as the military tries to expel the anti-Assad fighters.

The SANA state news agency said “terrorists” fired mortar rounds that struck a bus station in the Damascus suburb of Jaramana, killing four people and wounding 20. The Syrian regime describes those trying to topple Assad as “terrorists.”

SANA said the attack caused significant damage to cars and buses parked at the station.

The Observatory, which relies on a network of activists on the ground, also reported that four civilians died after being tortured in a jail in the town of Zakyeh. It did not provide any further details.

Syria’s rebels ― a mosaic of various factions with different ideologies and no united command ― have pried much of the country’s north from regime forces, and captured their first provincial capital ― the city of Raqqa along the Euphrates River ― last month.

Rebels also have made significant gains in recent weeks in southern Syria near the border with Jordan, capturing military bases and territory that could provide anti-Assad fighters with a staging ground for an eventual assault on Damascus.

The push in the south has coincided with what Western and Arab officials say is U.S.-backed training of opposition fighters in Jordan and an influx of foreign-funded weapons into the south. The rebel advances have given the opposition momentum and put the government on the defensive in the two-year civil war that the U.N. estimates has killed more than 70,000 people.

The fighting has spilled over on several occasions into neighboring states, including Lebanon, Turkey and Israel, stoking fears that those countries could be dragged into the conflict.

On Sunday, two rockets fired from Syria exploded in the Lebanese border village of al-Qasr, killing one person and wounding two, a Lebanese security official said on condition of anonymity because he was not authorized to brief reporters. Two more rockets landed in a nearby village of Hawsh, killing a 13-year-old boy and damaging two homes, the official said.

It’s unclear who fired the rockets from Syria, the official said.

There has been heavy fighting near the frontier in recent days as Syrian government troops try to regain control of the strategic area from rebels.

Also Sunday, the main Western-backed opposition bloc expressed concern about the Islamic extremist rebel faction Jabhat al-Nusra’s pledge of allegiance to al-Qaida last week.

In a statement, the Syrian National Coalition urged Jabhat al-Nusra, one of the most powerful and effective rebel groups, “to stay within the ranks of nationalistic Syrians, to continue its efforts in fighting the Assad regime, and in supporting and protecting the freedom of all Syrian sects.”

Jabhat al-Nusra’s pledge of fealty sparked concern that the allegiance to al-Qaida means the group will be beholden to non-Syrian interests.

But the broader rebellion desperately needs the extremist group’s fighting skills in its battle to oust Assad. Jabhat al-Nusra itself has sought to ease concerns by saying it remains dedicated to the Syrian uprising’s cause of toppling the Assad regime.

In the northern province of Aleppo, three journalists working for state TV were wounded in a car bombing Sunday, the state news agency said. Correspondent Shadi Helweh and two cameramen, Yehia Mosseli and Ahmed Suleiman, were hospitalized with shrapnel wounds, the agency said.

The journalists were reporting on Syrian soldiers who were trying to stop two suicide attackers attempting to detonate a car bomb near a security headquarters in the province. SANA said the two attackers were killed, and the journalists and several other civilians were wounded.