At least 12 people, including children, have been killed in three explosions in the northern city of Aleppo, Syrian activists say.
The director of the Britain-based Syrian Observatory for Human Rights, Rami Abdul-Rahman, says the blasts appeared to have been caused by missiles which hit the eastern neighbourhoods of Hamra and Tariq al-Bab today.
The Observatory says dozens of people were wounded, and that many more are believed to be trapped under the rubble of damaged buildings. It says the death toll may rise.
Videos posted online showed what appeared to be the aftermath of the explosions. In one, at least nine bodies are laid out on a floor, some of them wrapped in blankets. The videos appeared to be authentic.
Earlier Syrian warplanes and artillery reportedly hit targets near Damascus International Airport, following a bloody day of attacks in the Syrian capital that killed dozens and struck deep into President Bashar Assad's seat of power.
Syrian state media said the car bombing yesterday in the heart of Damascus - near the ruling Baath Party headquarters and the Russian Embassy - was a suicide attack that killed 53 civilians and wounded more than 200, including children. Anti-regime activists put the death toll at 61, which would make it the deadliest Damascus bombing of the revolt.
The main opposition group, the Syrian National Coalition, condemned the attack without accusing any specific group of carrying it out. It did, however, suggest that the regime allowed foreign terror groups to operate in Syria.
Today, the Coalition said it would welcome US and Russian mediation to negotiate a peace deal to end the country's civil war but insisted it would not allow Mr Assad or members of his security services to participate in the talks. The announcement came in a statement posted on the Coalition's Facebook page following two-day meetings in Cairo meant to try to firm up its position on whether to engage with the regime in talks.
"Bashar Assad and the security and military leadership responsible for the state of Syria today must step down and be considered outside this political process," the statement said. "They cannot be part of any political solution for Syria and must be held accountable for their crimes."