Also on Sunday, Syrian troops and allied fighters from popular defense groups were deployed to Arbin, located 9 kilometers east of Damascus, after the last group of militants left the town toward militant-held areas in northern Syria.
Syrian state TV separately said the army had freed the four women and a man from the militants as part of "efforts by the Syrian state to liberate all the prisoners in Douma".
Iyad Abdelaziz was quoted as saying by The Associated Press news agency on Sunday that there was no agreement reached to have the Jaish al-Islam rebel group leave Douma for north Syria and hand over the town to government forces.
The last Syrian rebel group in eastern Ghouta, near Damascus, has begun withdrawing under an agreement with the government, state media report.
Syrian government forces, backed by Russian Federation, have now recaptured almost all of eastern Ghouta, on the outskirts of Damascus, from the rebels in a ferocious assault that began in February, marking a major victory for President Bashar al-Assad.
The Russian General Staff says the rebel fighters are still leaving the town of Douma for the opposition-controlled north and the evacuation will wrap up in the coming days..
It was the first organized evacuation of fighters from Douma, one of the earliest centers of the anti-government demonstrations that swept through the country in 2011.
Jaish al-Islam, or "Army of Islam", had previously refused to leave the area.
Opposition officials, however, denied the reports.
The five had been abducted by the Army of Islam rebel group in Ghouta in 2013 along with many other civilians, it said. However, he said that "humanitarian cases" would be allowed to evacuate on Monday.
Dozens if not hundreds of residents are believed to require care for war wounds and medical conditions exacerbated by the siege of the town.
Local activists have said that over 100,000 civilians were trapped inside Douma, which suffered devastating damage.
Ahmad Ramadan, a prominent opposition figure in exile, told the Saudi TV channel al-Arabiya that the Army of Islam was still engaged in talks with Russian Federation over the future of the town.
The town of Douma was the final pocket of resistance to the Damascus regime in the embattled enclave.