Russia announced on Thursday that the Syrian regime flag was flying in the town of Douma, signalling President Bashar Al Assad's control of Eastern Ghouta.
The Syrian government, however, has yet to officially announce it has fully retaken Eastern Ghouta's main town – the last part of the former rebel enclave on the eastern edge of Damascus.
"Today a significant event in the history of Syria took place. The raising of a regime flag over a building in the town of Douma signified control over this town and consequently over Eastern Ghouta as a whole," Major General Yury Yevtushenko, head of the Russian military's centre for reconciliation in Syria, was quoted as saying by the Interfax news agency.
Russian television showed footage of the Syrian government's red, white and black flag with two green stars hanging from an unidentified building, while cheering crowds waved flags in among shell-damaged buildings.
An aide to Iran's supreme leader called the capture of the suburbs by the regime military one of the most significant victories of the war.
Speaking from Damascus on Thursday an aide to Iran's supreme leader said he hoped Syrian forces would soon move east of the Euphrates river and "expel the American occupiers".
Ali Akbar Velayati also said he hoped that rebel-held Idlib province would be next to fall to President Bashar Al Assad's forces.
The Russian defence ministry said its military police had begun patrolling Douma, after announcing their planned deployment the day before.
"From today, units of the Russian armed forces' military police are working in the town of Douma. They are a guarantee of the observance of law and order in the town," the defence ministry said in a statement, RIA Novosti news agency reported.
Russian military police have been in Douma this week as part of a deal with Jaish Al Islam, the rebel group that controlled the area for years.
Several thousands of its fighters were still in the town on Thursday and there was no immediate confirmation that any regime forces had entered the city.
The Russian military said the situation in Douma was normalising and a total of 166,644 people had been evacuated from the city through a humanitarian corridor.
A top Syrian rebel official told AFP on Thursday that his faction only agreed to abandon its battered enclave outside Damascus because of an alleged toxic gas attack.
"Of course, the chemical attack is what pushed us to agree" to a withdrawal from Douma, said Yasser Dalwan, a high-ranking member of the Jaish al-Islam faction that held the town.