Meanwhile, busloads of Syrian rebel fighters continue to depart the devastated city of Douma under a Russia-sponsored deal to evacuate thousands of rebels and their families from the besieged enclave. Our correspondent Alaa Ebrahim has more.

ALAA EBRAHIM DAMASCUS "Rebel fighters continue to leave Douma town, the last rebel holdout in Eastern Ghouta the suburb of Damascus that rebels gradually lost control over since the middle of February. They are heading to the northern town of Jarabulus. Wednesday, we saw the second convoy of buses carrying militants from the Army of Islam, one of the largest rebel factions in the country. It seems that the government is poised to take Douma within weeks if not days, in one of the most important and deadliest battles of Syria's seven year conflict. The government retaking Eastern Ghouta one of the closest rebel strongholds to the capital is considered by many a major turning point compared to that of Aleppo in 2016. But another turning point could be imminent as we hear more reports of a likely US military attack against Syrian government forces. And while the government isn't commenting publicly on the issue, sources close to the government suggest contingency plans are in place to minimize the repercussions of an American assault. But many here in Damascus fear that such a move would not only cause further destruction to the country's crumbling infrastructure but also drive the country into more violence as rebels could capitalize on the momentum of any US intervention - and stage new offensives of their own. Alaa Ebrahim - CGTN - Damascus."