BEIRUT (AP) — The Syrian government has given a final, three-day ultimatum to the largest rebel group in the enclave of eastern Ghouta to leave the last remaining rebel-held town in the area, state TV reported on Thursday.

According to the TV report, the 72-hour deadline began on Wednesday night.

Talks have been deadlocked for days between the Army of Islam group, which controls the Syrian town of Douma, just outside of Damascus, and Russian mediators.

The Syrian government and its Russian backers have insisted that Army of Islam members leave the area for northern Syria.

Army of Islam spokesman Ammar al-Hassan said the government is insisting that the group's fighters move north but that they have rejected such demands.

Pro-government media have warned of an all-out offensive on Douma if the rebels don't withdraw.

In Moscow, the Russian defense minister said Syrian rebels attempted to put dozens of suicide attackers on buses evacuating residents from Damascus' eastern suburbs.

Sergei Shoigu said during Thursday's meeting with visiting U.N. envoy to Syria Staffan de Mistura that the Russian military received a tip about the planned attacks from locals in eastern Ghouta and disarmed the would-be attackers.

Shoigu said the military found seven belts packed with explosives for suicide missions on Monday, another 32 on Tuesday and nine on Wednesday.

"It's easy to imagine what would happen if those suicide attackers blew themselves up on the buses carrying women and children," Shoigu added.

He said that 130,000 civilians and 11,000 rebels have so far left eastern Ghouta over the past two weeks.

De Mistura, who also met with Russian Foreign Minister Sergey Lavrov, said after their talks that it is essential to ensure the safety of civilians being evacuated from eastern Ghouta.

He noted that he had discussed provisions for the U.N. humanitarian assistance in eastern Ghouta and other regions of Syria. De Mistura also emphasized the need to give a new impulse to the talks on the political settlement in Syria.