BEIRUT (AP) — Government forces and rebels battled in the suburbs of Damascus and elsewhere in Syria on Tuesday as the first group of Russian citizens prepared to be evacuated from the country to escape nearly two years of conflict.

Russia is sending two planes to Lebanon to start evacuating its citizens from Syria, the strongest sign yet that President Bashar Assad’s most important international ally has serious doubts about his ability to cling to power.

Russian officials said Monday that about 100 of their citizens in Syria will be taken out overland to Lebanon and flown home from there, presumably because of renewed fighting near Damascus airport. They also said thousands more could follow — many of them Russian women married to Syrians — and later evacuations could be by both air and sea.

The Britain-based Syrian Observatory for Human Rights said clashes between opposition fighters and troops were concentrated in the areas around the capital, including along the road linking it to the international airport. Persistent fighting along the airport road has prompted regional and international airlines to suspend flights to Damascus in recent weeks, although Syrian officials maintain that the airport facility remains open.

No casualties were immediately reported in Tuesday’s fighting.

The Observatory said government forces have renewed artillery shelling of the central city of Homs, adding that several shells also hit the southern opposition stronghold of Daraa and the rebellious neighborhoods outside Damascus that the Syrian army has been trying to rid of rebels, posing a threat to the capital which is the seat of Assad’s power.

Russia has been Assad’s main ally since the uprising against him began in March 2011, using its veto power in the U.N. Security Council to shield Damascus from international sanctions for brutal crackdown on dissent.

Assad has dismissed calls that he step down, claiming that the country is fighting Islamic extremists and terrorists. He has proposed a national reconciliation conference, elections and a new constitution, but the opposition insists he play no role in a resolution to the conflict.

Last month, Russia started distancing itself from Assad, with President Vladimir Putin saying that he understands Syria needs change and that he was not protecting the Syrian ruler.

Syrian conflict began as peaceful protests against Assad’s rule but turned into civil war that has claimed more than 60,000 lives, according to a recent United Nations estimate.