Syrian forces, backed by intense air bombardment, have gained territory on the edge of Douma - the last rebel pocket in Eastern Ghouta near the capital Damascus.
The government forces have seized at least 50 farms in the vicinity of Douma in the fight against the rebel Jaish al-Islam rebel faction, which controls the town, the Syrian Observatory for Human Rights said.
On Friday, the government military started a major offensive against Douma, shattering 10 days of calm in the town.
Supported by airpower from allied Russians, the Syrian forces intensified attacks on Douma in an attempt to cement its control of long-besieged Eastern Ghouta, according to the Observatory.
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At least eight civilians were killed in Saturday's bombardment of Douma, bringing to 48 the number of civilians who have been killed in the town since Friday, the Britain-based watchdog added.
Syria's state news agency SANA said the bombardment was in response to shelling by Jaish al-Islam rebels on residential areas in Damascus. SANA reported unspecified casualties and material damage as a result of the shelling.
Rebels have repeatedly fired shells from Eastern Ghouta at government-controlled areas in and around Damascus, the seat of power for Syrian President Bashar al-Assad.
The Observatory said at least 15 civilians had been killed by shelling targeting the centre and outskirts of Damascus during the past 24 hours.
On Thursday, evacuations of civilians from Douma were suspended, days after hundreds of opposition fighters and their families safely left Douma under a Russian-brokered deal.
In recent weeks, government forces have retaken most of Eastern Ghouta through a combination of ground assaults and Russia-brokered evacuation deals.
Some opposition groups have condemned these evacuations as forced displacements.
Eastern Ghouta has been besieged by forces loyal to al-Assad for more than four years.
Should the government recapture Eastern Ghouta, it would deal the harshest blow to the rebels since December 2016, when al-Assad's forces regained full control of the northern city of Aleppo following a Russian-backed campaign.