A music festival in southern Israel ended in tragedy over the weekend, leaving hundreds dead after a surprise Hamas attack.

Universo Paralello, which originated in the Brazilian state of Bahia, was dubbed the “Supernova” festival and was set to take place on Friday and Saturday, bringing thousands of people to the Israeli desert of Negev in Re’im near the Gaza border to coincide with the Jewish festival of Sukkot. Before the festival began, organizers took to social media to announce “the time has come when the whole family is about to get together again.”

However, just hours later, people were fleeing the festival in panic, searching for their loved ones amid mass chaos. A spokesperson for the Israeli nongovernment rescue and recovery organization ZAKA said a total of 260 people were killed at the event.

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According to Israel Channel 12, the first sign that something was wrong was a siren, declaring rockets were fired off. One festivalgoer, Ortel, told the publication that the electricity was turned off and 50 terrorists arrived in military uniforms. Gunfire followed, with shooting in every direction.

“They fired bursts, and we reached a point where everyone stopped their vehicles and started running,” Ortel told Channel 12. “I went into a tree, a bush like this, and they just started spraying people. I saw masses of wounded people thrown around and I’m in a tree and trying to understand what’s going on.”

While festivalgoers knew it was a possibility that rockets could be fired in the area, they were shocked by the gunfire. Hundreds tried to escape in their cars, but the roadways became stalled and there was shooting in every direction. An attendee described their experience to Reuters, noting that she got inside a car to escape but the driver was shot point blank, forcing her to play dead until she was rescued.

Attendee Shoam Gueta told NBC News that he hid in the bushes for nearly six hours, watching people die around him. He told everyone in his group to stay silent and to not run away, even when the militants were close by.

“We saw terrorists killing people, burning cars, shouting everywhere,” Gueta described to NBC. “If you just say something, if you make any noise, you’ll be murdered.”

A medic named Yaniv described the event as a “massacre,” telling Kan News that it was a “planned ambush.”

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“As people came out of the emergency exits, squads of terrorists were waiting for them there and just started picking them off,” Yaniv said. “There were 3,000 people at the event, so they probably knew it. They had intelligence information.”

Amid the gunfire, people were kidnapped and taken hostage. In one viral video, festivalgoers identified by CNN as Noa Argamani and Avinatan Or are shown being kidnapped, with Argamani being taken away on the back of a motorcycle. Hundreds of others have gone missing, with many taking to social media to attempt to locate them.

Among those killed is a 30-year-old German tattoo artist named Shani Louk. The Daily Mail reported that Louk’s body was paraded in the back of a Hamas pick-up truck while militants sat on top of her and cheered. A British citizen, Jake Marlowe, was working security at the festival and is still reported missing.

According to the BBC, at least 700 Israelis have been killed since the attack began, local media outlets report, and the fight between Israeli military and Palestinian militants has continued. The air strikes on Gaza have killed at least 493 people, according to Palestinian officials.

“The Universo Paralello team, appalled, shocked and outraged by the attack on innocent lives, clarifies some information about the Festival’s link with the @tribe_of_nova Universo Paralelo Edition event, which took place in the region,” Universo Paralello shared on Instagram. “The attack was not only in the region of the event, but simultaneously orchestrated across the country with more than 2,000 missiles.”

Once again, we are appalled, shocked and frightened by everything that happened and we explicitly leave our revolt and our feelings to the victims of this heinous attack.

Festival organizers said in a statement on social media that they are working with Israeli security forces to help find the missing attendees.

“We send strength and share the sorrow of the missing and murdered. We are doing the best we can to help the security forces, maintaining constant contact with them and are positioned in the area taking part in searches in order to locate the missing.”

Music festivals are common in Israel, bringing in people from the country, as well as across the globe. An Israeli ambassador to the United Nations, Gilad Erdan, told NBC News that a “few” Americans were in attendance.

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