The media quoted eyewitnesses who spoke of a massacre. Videos circulating on the internet are said to show the revellers fleeing from the shots of the attackers.

It is unclear whether the festival dead are included in the current total of at least 700 people killed, that several Israeli media reported, citing medical sources. More than 2,000 are reported injured.

Israeli retaliatory attacks on Gaza later killed 413 Palestinians and injured almost 2,300, the Health Ministry there said.

Thousands of young people attended the Nature Party, near Kibbutz Re’im close to Gaza, which became one of the first targets of Palestinian gunmen who crossed into Israel early on Saturday in the biggest attack on the country in decades.

Arik Nani, who went to the dance party in southern Israel to celebrate his 26th birthday ended up fleeing a massacre as missiles roared overhead and Hamas gunmen shot down people as they tried to escape.

“I heard shots from every direction, they were firing at us from both sides,” Nani said. “Everyone was running and didn’t know what to do. It was total chaos.”

As rocket fire exploded around, panicked party goers tried to escape in any way they could.

“At one stage me and a friend got into a car with people we didn’t know and we just jumped into a car with lots of people and started to drive,” said 23 year-old Zohar Maariv. After the car came under fire, they fled on foot and hid for hours until they were rescued. But her boyfriend Matan, who had worked at the party, was still missing.

“Only this morning did I understand the scale of what happened, that what had happened was not only at the party, it’s the whole south is on fire,” Maariv said.

After hours of running, Nani and his friend finally reached shelter where he heard horrifying stories from others who had escaped. “People speaking about murder they saw in front of their eyes, someone who saw an entire kidnapped family and a small girl who was murdered,” he said.

Noa Argamani and her boyfriend Avinatan Or were also at the party but did not make it home.

They are now identified among dozens of Israelis apparently held captive in Gaza after video circulated showing Noa being carried away on the back of a motorcycle, pleading and reaching out towards her boyfriend being marched alongside on foot.

As warning sirens sounded across southern and central Israel when the missiles started flying in the early hours of Saturday, people started trying to contact friends and relatives.

“We started texting everyone,” Amit Parpara, a friend, told Reuters. Other friends at the party managed to escape in their cars, he said but at first it was impossible to get in touch with Noa or Avinatan until he received a text himself.

“She texted me her live location and a message that says ‘I hope someone can come save us,’” he said.

He said he had seen photos of the pair hiding in a hole, waiting for rescue.

Yaakov Argamani, Noa’s father, told Channel 12 television that he had seen the footage of his daughter being driven away on the motorbike and confirmed her identity.

“She was so terrified. I always protected her and in this moment I couldn’t.”

dpa and Reuters