LARNACA, Cyprus (AP) — Tomer Bassis expected his day to be filled with electronic trance music at the Oct. 7 desert rave party he was attending in southern Israel. Instead, the sounds of bullets whizzing by as he ran to escape the indiscriminate gunfire of Hamas militants became the soundtrack seared into his mind.

The 25-year-old Israeli was among some 3,000 other young revelers at the music festival who fled the carnage as the militants from Gaza descended on the field, gunning down young men and women and throwing rocket-propelled grenades into the crowd in an unprecedented rampage.

The open-air Tribe of Nova music festival is believed to be the worst civilian massacre in Israeli history, with at least 364 dead. In a single day, Hamas and other Palestinian militants killed about 1,200 people in Israel, mostly civilians, and took around 240 people captive.

Bassis remembers that as he ran, a girl he didn't know was running next to him.

“I looked to the left and she got hit with the bullet in the head and fell down immediately,” he said. He kept on running, screaming, “I’m sorry, I’m sorry that I couldn’t help you.”

“And all the time bullets are whistling,” he said. “I see people falling.”

The traumas of that horror-filled day are what Bassis — along with some 50 other young survivors of the rave attack — has tried to come to terms with during a five-day retreat at Secret Forest, a site owned by Israel in the hills above Cyprus’ southwestern coastal resort town of Paphos.

Another survivor, Eyal Sirota, 24, said the program was aimed at giving him and others the “tools to deal with the pain and the stress” of what they experienced and witnessed.

Some of the coping tools they are taught include breathing techniques and discussions — “sharing everything with each other.” The daily sessions are complemented with yoga, meditation, reflexology, massage and acupuncture, Sirota said.

Rabbi Arie Zeev Raskin, who heads Cyprus’ small Jewish community, said Bassis and Sirota were part of the sixth group of around 50 survivors of the Oct. 7 attack brought to the retreat this week to undergo five days of rest, relaxation and therapy in Cyprus.

Raskin said Cyprus’ close proximity to Israel and cheap flight connections make it an ideal destination for such a retreat — a place of calm that can help those who survived the Hamas attack heal, at least a little.

The trips to Cyprus are supported by NovaHelp, a group of mental heath professionals who came together to help survivors of the rave party, said Raskin. Financial support is provided by other charities and private businesses, including major accounting firms and Jewish American groups.

Raskin has initiated another, similar project currently underway to bring parents who lost children during the Oct. 7 attack to undergo similar therapy in Cyprus.

Some 1,200 Israelis were killed during that single day of Hamas' onslaught. Israel responded with devastating airstrikes and a ground offensive into Gaza. The war has so far killed more than 13,300 Palestinians, according to the Health Ministry in Hamas-controlled Gaza, which doesn’t differentiate between civilians and combatants.

On their final day before heading back to Israel on Thursday, Bassis' group of survivors were treated at the Jewish Community Center in the coastal town of Larnaca to a meal of hummus, kosher meats and plenty of drink to the pounding rhythms of Israeli pop and trance music.

They all clapped and sang along to the music as they celebrated life.

But despite festive moments, the terror of that day still haunts Bassis.

He recounted trying to avoid a massive car jam as he ran, hundreds of vehicles chaotically trying to flee the shooting.

When he couldn't run, he tried to hide where he could — first under the stage that was used for the rave party, and finally, under an Israeli armored vehicle where he held a young wounded woman in his arms until help came.

It was there that later, Bassis said he sprang into action and helped with the evacuation of some of the wounded.

Six of his friends who were with him at the rave did not survive.

“I will keep dancing and I will keep partying for my friends," said Bassis. “I will dance for them, I will live for them. I will make my life the best for them.”

“I got my life as a gift back," he said. "I will not waste it.”