Russia says more than 11,000 people have left Syria's besieged eastern Ghouta during the past few hours as government forces step up an offensive on the rebel enclave.

According to a spokesman for the Russian center for reconciliation of the warring parties in Syria about 3,000 people have been leaving every hour through a government-run humanitarian corridor monitored by the Russian military.

More than 150,000 people have so far left the town in the last few days.