EU foreign ministers will on Tuesday hold urgent talks on the situation in Israel and Gaza after Hamas militants launched a surprise assault, the bloc's foreign policy chief Josep Borrell said.

"I am convening tomorrow an emergency meeting of EU Foreign Ministers to address the situation in Israel and in the region," Borrell wrote in a social media post Monday.

Borrell and a number of EU foreign ministers are currently in Oman for long-planned talks with Gulf states from the Gulf Cooperation Council.

A spokesman in Brussels said the EU talks would be held in a hybrid video and in-person format to allow those foreign ministers not in Muscat to participate.

The EU has strongly condemned the unprecedented attack by the Islamist militants that has sparked a barrage of strikes by Israel on Gaza.

More than 700 Israelis have been killed and at least 100 kidnapped in the assault that has left the country reeling and sparked fears of a broader escalation in the region.

The reprisal bombing campaign by Israel in Gaza has killed 493 people, according to Palestinian officials.