The strikes near Damascus came less than 24 hours after the end of a Gaza truce between Hezbollah ally Hamas and Israel.

"Two Syrian fighters working for Hezbollah were killed and seven other fighters working for the group were wounded in Israeli air strikes on Hezbollah sites near Sayyida Zeinab," said Rami Abdel Rahman, who heads the Syrian Observatory for Human Rights.

Israel has launched hundreds of air strikes on its northern neighbour since Syria's civil war began in 2011, primarily targeting Iran-backed forces and Lebanese Hezbollah fighters, as well as Syrian army positions.

But it has intensified attacks since its war with Hamas began in October. Hamas last year said it had restored relations with Syria's government.

The chief of the British-based monitor, which has a network of sources inside Syria, had earlier told AFP that Israel struck "Hezbollah targets" in the Sayyida Zeinab area south of Damascus.

Syria's defence ministry had also said Israel hit near the Syrian capital, with an AFP journalist in Damascus reporting the loud sound of bombings.

"At approximately 1:35 am (2235 GMT) today, the Israeli enemy carried out an air assault from the direction of the occupied Syrian Golan, targeting some points near the city of Damascus," the defence ministry said in a statement, reporting no casualties.

Syria state television had reported an "Israeli aggression near the capital".

The Israeli army did not comment when contacted by AFP.

On November 8, Israeli air strikes on the same area near Damascus killed three pro-Iran fighters as they hit sites belonging to the powerful Lebanese group, the Observatory had said.

Israeli air strikes on November 26 rendered Damascus airport inoperable just hours after flights resumed following a similar attack the month before.

Damascus and Aleppo airports were both put out of service following Israeli strikes on October 12 and 22.

Israel rarely comments on individual strikes targeting Syria, but it has repeatedly said it will not allow arch-foe Iran, which backs Syrian President Bashar al-Assad, to expand its presence there.

Hezbollah is an ally of Damascus and has long fought alongside Assad in the country's war.