Damascus, backed by Russia and Iran, are waging one of the deadliest assaults of the war in eastern Ghouta. At least 600 people have been killed since February 19 by fierce air and artillery bombardment.
Syrian regime forces seized territory inside Syria's rebel eastern Ghouta on Saturday, intensifying fighting as tens of thousands of civilians in the besieged enclave near Damascus awaited urgently needed aid.
Syria's war has killed more than 340,000 people and spiralled into a complex conflict involving world powers since starting in 2011 with the brutal repression of anti-government protests.
Russia-backed regime forces have since February 18 killed more than 640 civilians – including over 150 children – in a ferocious bombardment of eastern Ghouta, one of the armed opposition's last strongholds in the country.
Following a deadly wave of air strikes and shelling, fighting on the ground has intensified in recent days, and the regime now "controls 10 percent of the besieged eastern Ghouta region", the Syrian Observatory for Human Rights said late on Saturday.
Regime forces have advanced steadily since Thursday, the Britain-based monitor said earlier, recapturing two areas in the east and southeast of the enclave on Saturday alone.
"Regime forces and their allies have intensified their attacks on rebel positions in the past 48 hours," Observatory head Rami Abdel Rahman said.
Eastern Ghouta's 400,000 residents have lived under regime siege since 2013, facing severe food and medicine shortages even before the latest offensive.
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'Scorched earth policy'
The fighting on the ground comes after Russia on Tuesday started a daily five-hour "humanitarian pause" in the enclave – a move that falls far short of a 30-day ceasefire demanded by the UN Security Council.
The ferocity of the bombardment initially lessened but it has continued to claim lives, and trucks loaded with desperately needed aid remain unable to enter the enclave.
Thousands of civilians are surviving on meagre stocks, and medical staff struggle to treat casualties with inadequate medical supplies.
The UN Human Rights Council postponed voting Friday on a British resolution condemning the crisis in eastern Ghouta, after member states failed to agree on a final text.
Moscow has offered safe passage to non-combatants wishing to leave the enclave during the pause, but no Syrian civilians have left since Tuesday, the Observatory says.
The Russian military said in a statement that no civilians exited via the established corridor on Saturday.
Government fighters are trying to advance inside Eastern Ghouta to cut off the main town of Douma and its surroundings in the north of the enclave, as well as isolate the southeastern area of Al Marj, Abdel Rahman said.
Jaish al Islam, a main opposition group in the region, accused regime forces of carrying out a "scorched earth policy" as they progressed into the enclave.
Opposition fighters abandoned their positions confronted with "hysterical bombing" in agricultural areas in the east, Jaish al Islam spokesman Hamza Bayraqdar said on Telegram.