An Islamist suicide bomber killed at least 50 Syrian security men in Hama province, opposition activists have said.
Syrian state media reported that a suicide bomber had targeted Sahl al-Ghab, but put the death toll at two.
Head of the Syrian Observatory for Human Rights, Rami Abdelrahman, said the centre was used by security forces and pro-Assad militia as one of their biggest bases in the area.
Mr Abdelrahman said a fighter from the Nusra Front blew himself up after driving his car to the centre.
The Nusra Front, an al Qaeda-inspired group of ultra-orthodox Salafi Muslims, has claimed responsibility for several suicide bombings in Damascus in the past.
Meanwhile, warplanes fired rockets and tanks and artillery pounded the neighbourhoods of Sbeineh, Yalda, Bibla, al-Tadamun and Hajar a-Aswad, activists said.
The working-class Sunni Muslim neighbourhoods have been at the forefront of the 19-month-old revolt against Mr Assad, whose Alawite faith derives from Shia Islam.
Rebel Free Syrian Army fighters attacked a pro-Assad militia in the southern neighbourhood of Nisreen overnight, an area mainly populated by members of Mr Assad's minority Alawite sect.
In Damascus, a car bomb exploded in the mostly Alawite western district of Mezzeh 86, killing 11 people and wounding dozens more, including children, state media and the Syrian Observatory reported.
Warplanes, tanks and artillery battered rebel-held parts of southern Damascus in what one Western diplomat said was an escalation in the government campaign to crush the insurgency.
Call for UN Security Council resolution
The international mediator on Syria, Lakhdar Brahimi, yesterday called for world powers to issue a UN Security Council resolution based on a deal they reached in June to set up a transitional government in a bid to end the bloodshed.
Russian Foreign Minister Sergei Lavrov, speaking at the same Cairo news conference, dismissed the need for a resolution and said others were stoking violence by backing rebels.
His comment highlighted divisions and the impasse over Syria's civil war.
Russia and China, both permanent council members, have vetoed three Western-backed UN draft resolutions condemning President Assad's government for the violence.
The other three permanent members are the United States, Britain and France.
Peaceful protests began in Syria in March 2011 but turned into an armed revolt after Mr Assad turned his military on the demonstrators. About 32,000 people have been killed.
The Geneva Declaration, that was agreed on 30 June when Kofi Annan was still international mediator, called for a transitional administration but did not specify what role, if any, Mr Assad would have.