'The horror': Israeli collecting corpses near Gaza

Yossi Landau has spent decades collecting corpses in Israel, but he almost reached breaking point recovering the remains of people killed by Gaza militants in the country's deadliest assault.

Landau woke to the sounds of sirens on Saturday, a moment he had become "used to" as Israelis took shelter from incoming rocket fire.

It was not until later that he realised the launches were "only a cover up, because the main part is the invasion" by Hamas militants, who swept across the Gaza border to kill an estimated 1,200 people. 

From his home in Ashdod, a coastal city north of Gaza, he recalled seeing "the horror" as he rushed to the scene.

"I saw cars turned over, I saw people on the street dead," Landau said in Sderot, a town near the border where multiple residents were killed.

He has 33 years of experience volunteering for Zaka, an organisation which recovers the bodies of people who suffered unnatural deaths.

But as gunfights raged between Palestinian militants and Israeli forces, Landau said he witnessed violence he had never seen before.

"A piece of road that should've taken 15 minutes, it took us 11 hours because we went and picked up everyone, put them in a bag," said the 55-year-old.

Abandoned cars which were torched or riddled with bullet holes still litter the landscape of southern Israel.

After already loading dozens of corpses onto refrigerated trucks, Landau and fellow volunteers reached Beeri, a kibbutz of around 1,200 residents five kilometres from Gaza.

"I felt that I'm falling apart, not only me, my whole crew," he recalled, after entering the first home and finding a dead woman.

"Her stomach was ripped open, a baby was there, still connected with the cord, and stabbed," said Landau.

The Zaka volunteer said he saw multiple civilians, including around 20 children, who had their hands tied behind their backs before being shot and torched.

"We saw some victims positioned that they were sexually abused," he added.

Stricken festival site

More than 100 people were killed in the kibbutz, while around 270 were left dead at the nearby Supernova music festival.

While the bodies of the revellers have been removed from the site, their belongings were left strewn across the dusty grass.

When journalist visited on Thursday, beanbags, artworks and a bag of energy drinks were among the possessions on the ground as soldiers walked by.

Blood splattered the inside of a car, not far from a sign detailing hiking routes through the forest.

Although Israel said it has retaken control of the border area, the army still reports firefights with holdout militants.

The military announced soldiers had "killed a terrorist" around a kibbutz a few kilometres away from the festival grounds on Thursday, soon after distant gunfire was heard from the site.

In response to the Hamas assault, Israel has so far hit Gaza with 6,000 bombs according to military figures.

The strikes have killed 1,417 Gazans, according to health officials in the Palestinian territory.

Confronting with the scale of violence, Landau said he doesn't "feel anything right now."

"We just take our feelings, with our job, and we separate it. And that's what we have to do," he said.