“Security police blocked off the square where the Baath’s Damascus branch is located. But I saw smoke rising from the building and fire trucks around it,” one witness, who declined to be named, told Reuters.

“The attack was just before dawn and the building was mostly empty. It seems to have been intended as a message to the regime,” he said.

The Syrian Free Army, comprised of army defectors and based in neighboring Turkey, claimed responsibility for the attack, just as Assad vowed in an interview to crush the insurgency and pursue a crackdown on protests demanding his removal that has killed 3,500 people, by a U.N. count…

Damascus-based journalist Thabet Salem, who lives about 1100 yards away from the Baath party building and heard the explosions, said if the reports are confirmed, it would signal a new phase in the Syrian uprising.

“It would be an escalation that gives a new dimension to the whole situation,” he said.