Seven years of conflict in Syria have left more than 350,000 people dead, according to an updated overall death toll released yesterday by the Syrian Observatory for Human Rights.

The Britain-based monitoring group, which relies on an extensive network of sources on the ground across Syria, said 353,935 people have been killed since March 15, 2011.

The conflict, which will enter its eighth year on Thursday, is taking a devastating toll on civilians, including in the ongoing regime assault on the rebel enclave of Eastern Ghouta, near Damascus.

Meanwhile, Syrian regime forces advanced against rebels in Eastern Ghouta and pounded two towns with air strikes yesterday, as they moved closer to retaking the opposition enclave on the edge of Damascus.

Three weeks after launching a fierce offensive to capture the region, forces loyal to President Bashar al-Assad have overrun more than half of Ghouta, whittling down rebel territory to three isolated pockets.

Pro-regime forces advanced again in Ghouta on Monday, using Medeira, a town captured on Sunday, as a base to push against areas closest to the capital, according to the monitor, the Syrian Observatory for Human Rights.

"The army used (Medeira) as a launching pad towards Harasta and Arbin," Observatory chief Rami Abdel Rahman said.