Photographer's pictures show the moments before Hamas attacked a music festival in Israel up until festival-goers took cover on the ground: 'It changed in a moment'

• A photographer captured moments of joy and revelry at the Nova Music Festival in Israel.
• Young people danced to electronic music all night, before Hamas militants attacked.

A photographer spent hours capturing photos of partiers laughing and dancing the night away at the Tribe of Nova music festival in Israel — right up until the moment festival-goers took cover from a barrage of bullets as Hamas militants attacked the area, killing hundreds.

Ido Derby, a 20-year-old photographer from Rishon LeTsiyon near Tel Aviv, told Insider he was part of the crew hired to capture the outdoor festival.

About 3,500 people gathered to listen to electronic music at the all-night event over the weekend about 3 miles from Israel's border with the Gaza Strip.

He shared photos with Insider showing how joyous the festival was before Hamas militants attacked.

"At the start of the festival, we were very excited," Derby told Insider, adding that he was taking photos for about six or seven hours.

"It was a huge festival and a chance for us, photographers, to capture one of these days," Derby added.

"It was like the hugest festival to arrive in our country," Derby said. "We used to go out and celebrate. We loved the festival, the music, the people, the vibe."

The photos Derby took before the attack show throngs of young people decked out in glitter and flowy festival outfits dancing and smiling under the neon lights to the trance music.

In some photos, festival goers are giving personal light shows. In another, a woman is hula-hooping, and a man is juggling light-up sticks. In one photo, a couple shares a romantic kiss.

Then, the explosions began.

Derby said at first, he didn't think anything of the sounds because he was used to them in Israel.

"I couldn't realize that my life was in danger," Derby said. "When I hear sirens or hear missiles, I'm not panicked. When tourists come to our country and hear sirens, it's maybe traumatic for people, but for me, I see missiles, and it's very interesting."

But soon, the music stopped, and a voice could be heard overheard warning of a "red alert," according to the Washington Post.

Hamas militants from Gaza infiltrated the crowds, gunning down festival-goers and taking others captive as hundreds attempted to run or hide in trees and bushes, Insider previously reported.

"It changed in a moment," Derby told Insider. "I was very upset that the festival ended because of terror."

Before fleeing, Derby took one final photo, showing a person ducking for cover with his hands covering his head — a stark contrast to the pictures of joy and revelry taken in the hours and minutes before.

"That photo — we took it at 6:30 a.m.," Derby said. "It was like five minutes after the first missiles started, shot above us."

Derby told Insider he was eventually able to escape in a car with friends, but as he looked through the rearview mirror, he saw bodies falling behind him.

At least 260 people were killed at the festival, and some are still missing, according to the Associated Press. Israeli security forces are still clearing the area, and the death toll could rise, the AP reported.

About 700 people have died in Israel and about 400 in Gaza, according to Reuters.

Israeli Prime Minister Benjamin Netanyahu has formally declared war on Gaza and announced he's cutting off the flow of fuel, supplies, and food to the 2 million Palestinians living in the Gaza Strip.