Iran's unprecedented overnight attack on Israel has been "foiled", the Israeli military said Sunday, with hundreds of missiles and drones intercepted with the help of the United States and allies.

The attack which began late Saturday marks a major escalation of the long-running covert war between the regional foes, and comes against the backdrop of the ongoing war between Israel and Palestinian militant group Hamas in the Gaza Strip.

Countries around the world condemned Iran's strikes on Israel late Saturday, warning the attack threatened to further destabilize the Middle East.

Iran launched an unprecedented drone and missile attack on Israel, the Israeli army announced late Saturday, in a major escalation of the long-running covert war between the regional foes.

Residents have reported heavy Israeli fire in central Gaza, with regional tensions soaring after Iran threatened reprisals over a strike in Syria this month that killed two Iranian generals.

As talks for a truce and hostage release dragged on, fears that Iran could soon launch an attack on Israel prompted the United States to announce it was sending reinforcements to the Middle East as a deterrent.

Residents reported heavy Israeli fire in central Gaza on Friday, with regional tensions soaring after Iran threatened reprisals over a strike in Syria this month that killed two Iranian generals.

As ceasefire talks aiming to pause the six-month-old war dragged on, fears that Iran could soon launch an attack on Israel spurred France to recommend its citizens avoid travelling to the region.

Two Palestinians were killed early Friday in confrontations with Israeli forces in the Israeli-occupied West Bank, Palestinian medics and the military said. The Islamic militant group Hamas said one of those killed was a local commander.

The raid took place in the town of Tubas and the adjacent refugee camp of al-Faraa. The Palestine Red Crescent Society confirmed the two deaths and said three people were wounded, including one who sustained serious injuries.

France on Friday warned its citizens to "imperatively refrain from travel in the coming days to Iran, Lebanon, Israel and the Palestinian territories," the foreign minister's entourage told AFP.

Iran has threatened reprisals against Israel over a strike on the Iranian consulate in Syria on April 1 that killed seven Revolutionary Guards including two generals, sparking fears of an escalation of violence in the Middle East.

They set themselves a 48-hour deadline earlier this week, but on Thursday neither Hamas nor Israel had shown any signs of agreeing to a truce in Gaza despite pressure from international mediators.

The United States, Egypt and Qatar put together a framework for a deal that would include a six-week halt to fighting and the exchange of about 40 hostages for hundreds of Palestinian prisoners.

A senior Hamas official said Thursday that only a ceasefire can provide "enough time and safety" to locate Israeli hostages held across the Gaza Strip and ascertain their fate.

Negotiations for a ceasefire have been under way in Cairo since Sunday, but so far there has been no breakthrough on a proposal presented by U.S., Qatari and Egyptian mediators.

U.S. Secretary of State Antony Blinken has asked China's foreign minister and other counterparts to use their influence to dissuade Iran from striking Israel, the State Department said Thursday.

Blinken spoke by telephone over the past day to his Chinese, Turkish, Saudi and European counterparts "to make clear that escalation is not in anyone's interest and that countries should urge Iran not to escalate," State Department spokesman Matthew Miller told reporters.