An Australian man has described his terrified escape from a music festival with “bullets flying over our heads” as Hamas militants attacked, amid terrifying violence in Israel.

It came as Israel pounded the Palestinian enclave of Gaza, killing hundreds of people in retaliation for one of the bloodiest attacks in its history when Islamist group Hamas killed 700 Israelis and abducted scores more on Saturday (AEDT).

By Monday afternoon (AEDT), the toll from the outbreak of violence was believed to have topped 1100 – 700 in Israel and more than 400 in Gaza. The dead include 260 bodies recovered from the Supernova festival near Gaza, which came under attack on Sunday (Australian time).

Daniel Moritz said he was at Supernova with friends, when it came under fire.

“Around 6am, we noticed bombings above our head — no sirens, nothing went off,” he told ABC Radio Melbourne on Monday.

“Totally surprised, totally unaware and unprotected.”

He and his five friends decided to flee in their car straight away.

“We just came to the decision, our friends, to get out of there, leave our stuff, leave our tents — everything,” he said.

“Luckily, we parked really close to the entrance. We found a hole in the fence so we managed to get out faster.

“We started to head north, we thought we were protected, and suddenly a machine gun started going off, just shooting at us full force.

“We hear the whistles of the bullets flying over our heads, we’re ducking down in the car.”

Moritz and his friends managed to escape uninjured. He spoke to the ABC from his home in northern Israel.

“What’s going on right now in the country is chaos,” he said.

The rampage through Israeli towns by Hamas fighters on Saturday was the deadliest such incursion since Egypt and Syria’s attacks in the Yom Kippur war 50 years ago and has threatened to ignite another conflagration in the long-running conflict.

In response, Israeli air strikes hit housing blocks, tunnels, a mosque and homes of Hamas officials in Gaza, killing more than 400 people, including 20 children, in keeping with Prime Minister Benjamin Netanyahu’s vow of “mighty vengeance”.

“The price the Gaza Strip will pay will be a very heavy one that will change reality for generations,” said Defence Minister Yoav Gallant in the town of Ofakim, which suffered casualties and had hostages taken.

Beyond blockaded Gaza, Israeli forces and Lebanon’s Iran-backed Hezbollah militia exchanged artillery and rocket fire, while in Egypt, two Israeli tourists were shot dead along with a guide.

Appeals for restraint came from around the world, though Western nations largely stood by Israel while Iran, Hezbollah and protesters in various Middle Eastern nations lauded Hamas.

In southern Israel on Sunday, Hamas gunmen were still fighting Israeli security forces more than 24 hours after their surprise, multipronged assault of rocket

Israel’s military, which faces awkward questions for not thwarting the attack, said it had regained control of most infiltration points along security barriers, killed hundreds of attackers and taken dozens more prisoner.

The military said it had deployed tens of thousands of soldiers around Gaza, a narrow strip of land that is home to 2.3 million Palestinians, and was starting to evacuate Israelis around the frontier.

Israel has not released an official toll but its media said at least 700 people were killed, children among them. Military spokesperson Daniel Hagari called it “the worst massacre of innocent civilians in Israel’s history”.

Hamas also claims to have taken more than 100 hostages, some of whom have since died.

Among those thought to be held is German tourist Shani Louk, who had been at Supernova when Hamas militants stormed the area, opening fire and sending terrified partygoers fleeing into the desert.

Her mother, Ricarda, said she had seen a video of Shani “unconscious in a car” after being taken.

Holding up a picture of the 20-something on her mobile phone, Ricarda said in a social media appeal that her daughter had been “kidnapped with a group of tourists in southern Israel by Palestinian Hamas”.

“We were sent a video in which I could clearly see our daughter unconscious in the car with the Palestinians and them driving around the Gaza Strip,” she said.

“I ask you to send us any help or news. Thank you very much.”

Several Americans were killed by Hamas attackers, a White House National Security Council spokesperson confirmed, saying the US would continue to monitor the situation closely.

Australia’s Foreign Affairs Department is also working around the clock to confirm the welfare of Australians in Israel.

“We don’t have any further information to announce at this point in time but obviously we are concerned, as is the whole world – this is a place where citizens of the world do gather,” Prime Minister Anthony Albanese said on Monday.

Dozens held hostage

The shocking flare-up may undermine US-backed moves towards normalising relations between Israel and Saudi Arabia – a security realignment that could threaten Palestinian hopes of self determination and hem in Hamas’ main backer, Iran.

Tehran’s other main regional ally, Lebanon’s Hezbollah, fought a war with Israel in 2006 and said its “guns and rockets” stood with Hamas.

With debris from the attacks still strewn around southern towns and border communities on Sunday, Israelis were reeling from the sight of bloodied bodies in streets, cars and even their homes.

Palestinian fighters took dozens of hostages to Gaza, including soldiers and civilians, children and the elderly. A second Palestinian militant group, Islamic Jihad, said it was holding more than 30 of the captives.

The capture of so many Israelis, some pulled through security checkpoints or driven bleeding into Gaza, is another conundrum for Netanyahu after past episodes when hostages were exchanged for many Palestinian prisoners.

US President Joe Biden spoke to Netanyahu for the second day, saying in a post on the X that he expressed “my full support for the people of Israel in the face of an unprecedented and appalling assault by Hamas terrorists”.

Hamas fired more rocket salvoes into Israel on Sunday.

The United Nations said at least 70,000 Palestinians in Gaza were seeking shelter in schools it runs. It appealed for the creation of humanitarian corridors to bring food into Gaza.

-with AAP