A Syrian passenger jet with 200 people aboard has landed safely after a military helicopter clipped its tail in mid-air, reports say.

The helicopter crashed near the capital of Damascus, though it was not clear if there were any casualties in that crash or what had led the two aircraft to touch in mid-air.

No one on board the passenger jet was hurt, state TV said.

The close call came at a time when Syria is embroiled in a civil war between the supporters of President Bashar Assad and those trying to topple him. The 18-month rebellion has claimed the lives of more than 23,000 people, according to activists, and Syria has descended into chaos.

The Syrian government has increasingly been using helicopters and other aircraft in its fight against the rebels. Rebels have claimed to have shot down helicopters and warplanes in the past, although the regime has blamed most of the problems on mechanical difficulties.

In today's incident, the helicopter's rotor clipped the tail of a Syrian Arab Airlines jet, the state TV said. The passenger plane "landed safely at the airport and none of the 200 passengers were harmed," the report said.

The helicopter crashed south-east of Douma, a Damascus suburb that has witnessed repeated military crackdowns to purge fighters seeking to topple Assad. No further details were made available.

"We heard the sound of several explosions and some gunfire, and a few minutes later, we were told that a helicopter had crashed," said Mohammad Saeed, an activist in Douma.