DAMASCUS -- An explosion ripped through a police bus in the center of Syria's capital Friday, killing at least 10 people and possibly 25 in an attack authorities blamed on a suicide bomber, an official and state-run TV said.

Syrian television showed residents and paramedics carrying human remains, holding them up for the camera. Other footage showed a bus with blood on its seats, and cars with blown-out windows and riddled with shrapnel.

``This is a criminal terrorist act,'' a man shouted.

State television said 10 people have been confirmed dead, and authorities believe another 15 also had died based on human remains from the scene.

Television also said that 46 people were wounded. It did not specify the victims' identities, but a Syrian official, speaking on condition of anonymity because he was not allowed to speak publicly to the media, said the target of the attack appeared to be a bus carrying policemen.

The blast went off at an intersection in the central Damascus neighborhood of Midan on Friday, the start of the weekend in Syria and much of the Arab world.

Compared to many parts of the country which have been convulsed by the 10-month old uprising, Damascus has been relatively quiet under the tight control of ruthless security agencies loyal to President Bashar Assad.

But violence in the capital has been on the rise over the last two months. On Dec. 23, according to the Syrian authorities, two car bombers blew themselves up outside the heavily guarded compounds of the country's intelligence agencies, killing at least 44 people and wounding 166.

If the official account is correct, they would be the uprising's first suicide bombings. State-run TV said the al-Qaida terrorist network was possibly to blame.

The government has long contended that the turmoil in Syria this year is not an uprising but the work of terrorists and foreign-backed armed gangs.

The opposition however has questioned the government's allegations. It has hinted that the regime itself could have been behind the attack, noting it came during a visit by Arab League observers investigating Assad's bloody crackdown of the popular revolt.

Midan is one of several Damascus neighborhoods that has seen frequent anti-Assad protests on Fridays.

The uprising outside Damascus has also become increasingly violent in recent months as dissident soldiers break from the military to side with peaceful protesters, raising fears of civil war.

Air force Col. Riad al-Asaad, leader of the main armed group fighting the regime, denied responsibility for Friday's bus bombing in an interview with pan-Arab Al-Jazeera TV.

He said his organization, the Free Syrian Army, ``doesn't have the experience to carry out such explosions.'' He spoke from Turkey, where the group is based.(AP)