The strikes near the Syrian capital came less than 24 hours after the end of a seven-day pause in fighting between Israel and Hezbollah ally Hamas in the Gaza Strip.

"Two Syrian fighters working with Hezbollah and two IRGC officers were killed in Israeli air strikes on Hezbollah sites near Sayyida Zeinab" south of Damascus, said Rami Abdel Rahman of the Syrian Observatory for Human Rights.

"The two IRGC officers were the target of the Israelis. They struck immediately after the pair went into the Hezbollah site," said the head of the Britain-based monitor, which has a network of sources inside Syria.

The two officers died from their injuries, he said, adding that five other fighters were wounded.

On Saturday, the IRGC accused Israel of killing two of its members in Syria where they had been on an advisory mission.

"Mohammed Ali Ataei Shoorcheh and Panah Taghizadeh... were martyred by the Zionist usurper enemy while conducting an advisory mission in the Syrian Islamic resistance front," the Guards' Sepah News website said.

It did not say when or where they were killed.

Israel has launched hundreds of air strikes on its northern neighbour since Syria's civil war began in 2011, primarily targeting Iran-backed forces including 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.

- 'Israeli aggression' -

Syria's defence ministry had also said Israel hit near Damascus, where an AFP journalist heard 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 ministry said in a statement. It gave no casualty figures.

Syrian 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 Hezbollah fighters as they hit sites belonging to the powerful Lebanese group, the Observatory 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.