"Air defences intercepted Israeli missiles" over the skies of Damascus, the official SANA news agency said.

AFP correspondents in Damascus said they heard several loud blasts.

A military spokesman in Israel told AFP that its army "does not comment on foreign reports".

According to the Britain-based Syrian Observatory for Human Rights, the Israeli attack hit several targets.

"At least six Israeli missiles hit several positions belonging to regime forces and pro-Iran militias south of Damascus," Observatory head Rami Abdul Rahman told AFP.

"Air defences did not intercept a single target," he said, adding it was unknown if there were casualties and the extent of damage remained unclear.

Israel has launched hundreds of strikes in Syria since the start of its civil war in 2011.

It has targeted government troops, allied Iranian forces and fighters from the Lebanese Shiite militant group Hezbollah, saying its goal is to end Tehran's military presence in Syria.

It rarely confirms details of its operations in Syria but says Iran's presence in support of the regime is a threat and that Israel will keep up strikes.

The nine-year-old conflict in Syria has killed more than 380,000 people and displaced more than half of the country's pre-war population.