A government checkpoint comes under attack in Damascus.
Amateur video which could not be independently verified by Reuters appears to show an explosion that an opposition website said shows a "act of martyrdom" committed by two suicide bombers using a car.
This comes as government tanks patrol the streets of the capital city. Opposition activist say at least 109 people have been killed in an almost week-long government offensive.
More than 70,000 have been killed in the more than two year old conflict. A military stalemate has set in -- leaving much of country in ruins.
