Israel shot down a Syrian fighter jet with surface-to-air missiles on Tuesday after the plane infiltrated airspace it controls, the military said, in a rare incident that could provoke tensions.

The Israeli military said that it had completed "a humanitarian effort to rescue members of a Syrian civil organisation and their families".

The Syrian army and its allies made advances in the southwest that bring it closer to the Israeli-occupied Golan Heights border, state television and rebels said on Saturday.

Syrian rebels have agreed with government backer Russia to the negotiated surrender of a sensitive southwestern zone bordering the Israeli-annexed Golan Heights, a monitor said Thursday.

Air strikes on Tuesday killed seven civilians in a sensitive southwestern province of Syria bordering the Israeli-occupied Golan Heights, a war monitor said.

Dozens of Syrians approached the Israeli frontier on the Golan Heights on Tuesday in an apparent attempt to seek help or sanctuary from a Russian-backed Syrian army offensive, before turning back after a warning from Israeli forces.

Syrian government forces seized a village in Quneitra province on Sunday, their first advance against insurgents in the region adjoining the Israeli-occupied Golan Heights since launching a major offensive in the southwest, a war monitor reported.

Jordan, already hosting some 650,000 Syrian refugees, says its border will remain closed to more refugees.

President Bashar al-Assad is aiming to restore control over rebel-held areas at the borders with Jordan and the Israeli-occupied Golan Heights.

The Syrian army has seized a chunk of territory from rebels in the southwest, Syrian state media and a war monitor said on Tuesday, the first major government advance in an offensive near the Jordanian border which has displaced tens of thousands.

A war monitor reported Syrian military helicopters dropped barrel bombs on rebel-held areas of the southwest on Friday for the first time in a year.

Israeli jets and ground-to-ground missiles struck Syria early on Tuesday, Syria's army said, as Israeli Prime Minister Benjamin Netanyahu reiterated he would do what was needed to stop Hezbollah gaining "game-changing" Iranian weapons.