DAMASCUS: Rebels in Syria鈥檚 Eastern Ghouta surrendered their heavy weapons as their leader joined a convoy out of the enclave, a monitor said on Thursday, signalling an end to one of the bloodiest assaults of Syria鈥檚 seven-year war.

The Syrian flag was raised above the central mosque in Douma, the town where the regime is accused of carrying out a chemical attack that sparked outrage and threats of Western military action.

Jaish Al-Islam, which has controlled Eastern Ghouta鈥檚 main town for years, had balked at a Russian-brokered deal similar to those that allowed other factions to be bussed to northern Syria.

The group鈥檚 political chief told AFP that a chemical attack by the regime had forced them to accept Russia鈥檚 terms and leave their former bastion.

鈥淥f course, the chemical attack is what pushed us to agree鈥� to a withdrawal, said Yasser Dalwan.

Syrian regime forces had yet to take over Douma on Thursday, but according to the Syrian Observatory for Human Rights, the rebels had surrendered their heavy weapons.

鈥淛aish Al-Islam fighters handed over their heavy weapons to Russian military police in the town of Douma on Wednesday,鈥� the Britain-based monitoring group said.

Their leader, Issam Buwaydani, joined a convoy out of Ghouta with thousands of other fighters, it said.

鈥淣ot all the leadership has left yet. Departures are ongoing,鈥� Dalwan said.

Douma residents said Syria鈥檚 national flag was raised above the main mosque on Wednesday. But a dispute subsequently erupted, shots were fired and the flag was taken down.

Russian military police, who had started deploying in Douma as part of a deal that would allow some rebels to disarm and stay in the town, also left after the incident, residents said.

Simultaneously carrying out air strikes and supervising humanitarian operations, Russia was the key player in an assault that left at least 1,700 civilians dead.

鈥淭oday a significant event in the history of Syria took place,鈥� Maj. Gen. Yury Yevtushenko, head of the Russian military鈥檚 center for reconciliation in Syria, was quoted as saying by the Interfax news agency.

鈥淭he raising of a regime flag signified control over Douma and consequently over Eastern Ghouta as a whole,鈥� he said.

Moscow also said Russian military police had returned to the town and were in full control. 鈥淔rom today, units of the Russian armed forces鈥� military police are working in the town of Douma,鈥� the defense ministry said.