Israel hit a car used by Hezbollah in Syria, close to the Lebanese border, also striking near Damascus Thursday, a war monitor said, hours after similar attacks near the Syrian capital.

"An Israeli drone targeted a car belonging to Hezbollah in the Homs countryside near the Syrian-Lebanese border," said Rami Abdel Rahman, who heads the Syrian Observatory for Human Rights.

At the same time, "violent explosions resounded after Israeli strikes hit southwest of Damascus," said the Britain-based monitor with a network of sources inside Syria.

An AFP correspondent in Damascus said they heard faraway explosions.

On Wednesday evening, Israel struck near Damascus, killing two Syrian pro-Hezbollah fighters, the Observatory had said.

Last week, an Israeli strike on a truck in Syria near the Lebanese border killed two Hezbollah members, also according to the Observatory.

Hezbollah and other Iran-backed groups have been fighting alongside Syrian President Bashar al-Assad's forces following the eruption of civil war.

Since Syria's war began in 2011, Israel has launched hundreds of air strikes against its northern neighbour, primarily targeting pro-Iran forces, among them Lebanon's Hezbollah and the Syrian army.

But the strikes have multiplied during the almost five-month-old war between Israel and the Palestinian militant group Hamas.

Israel rarely comments on individual strikes but has repeatedly said it will not allow Iran to expand its presence in Syria.

Syria's war has claimed the lives of more than half a million people and displaced millions since it broke out in March 2011 with Damascus's brutal repression of anti-government protests.