CNN — An overnight Israeli airstrike on an area that Israel itself had designated as a humanitarian zone for displaced people in southern Gaza killed and injured dozens of Palestinians, according to local officials in the besieged enclave. Israel said the operation targeted Hamas fighters there.

At least 19 bodies arrived at hospitals from the humanitarian zone in Al-Mawasi. Earlier, Gaza’s Civil Defense said 40 people had been killed.

More than 60 people were also wounded in the strike, according to the Gaza Civil Defense, as rescuers raced to recover victims buried under sand and debris.

Eyewitnesses said that at least five missiles struck the area, according to the group. The explosion created three large craters, Gaza Civil Defense spokesman Mahmoud Bassal said.

The group said its crews were facing “great difficulty” in retrieving victims — many of whom were believed to have been sleeping at the time of the strikes — due to a lack of resources.

The Israel Defense Forces (IDF) said Monday evening that it “struck significant Hamas terrorists who were operating within a command-and-control center embedded inside the humanitarian area” in Khan Younis, Gaza.

Among those targeted were Samer Ismail Khadr Abu Daqqa, whom the IDF says was the head of Hamas’ aerial unit in Gaza, Osama Tabesh, who was “the head of the observation and targets department in Hamas’ military intelligence headquarters,” and Ayman Mabhouh, who it said was “another senior Hamas terrorist.”

The targets were “directly involved in the execution” of the October 7 attack on Israel and have been planning to “carry out terror activities” against the IDF and Israel, the IDF statement on Tuesday added.

The IDF provided no more information about the alleged militants. CNN is working to independently verify the claims.

Hamas denied it had placed fighters in the area. In a statement, it called Israel’s claims that its fighters were in the area “a blatant lie, through which it (Israel) seeks to justify these heinous crimes.”

The strike hit Al-Mawasi, a coastal region in Khan Younis where tens of thousands of displaced Palestinians have fled Israel’s bombardment from other parts of Gaza. Many are living in tents in an area with sparse infrastructure, scant access to shelter or life-saving humanitarian aid.

The Israeli offensive in Gaza since the Hamas-led October 7 attack on Israel has flattened neighborhoods, wiped out families and created a humanitarian disaster across the enclave. Israeli attacks in Gaza have killed 41,020 Palestinians and injured another 94,925 people, according to the Ministry of Health there.

CNN footage from the aftermath of the strike on Al-Mawasi showed dozens of people trying to recover the remains of their belongings. Poles that used to hold up tents protruded from the sand, but the material that covered their inhabitants was buried. Mattresses, blankets and clothes were scattered around another much bigger crater on the other side of the camp.

Some survivors pulled canned food from under the sand and a girl with an injured hand watched as those around her attempt to rebuild their tents.

“We were sleeping peacefully in our homes when, suddenly, rockets started falling heavily on us,” one survivor, Salem Abu Jara, told CNN. “Why are people being burned here?”

Families ‘disappeared in the sand’

Israel’s military said the operation was carried out with the direction of the Israel Security Agency and the Air Force, and that steps were taken to mitigate civilian harm “including the use of precise munitions, aerial surveillance, and additional means.” The military did not say whether it warned civilians in the area.

Hamas said “dozens of unarmed civilians, most of whom were children and women” were killed in the strike.

Gaza Civil Defense’s Bassal said Palestinians in the area were not warned of the strike in advance.

There were more than 200 tents of displaced people at Al-Mawasi area, Bassal said, adding about 20 to 40 tents were destroyed and “entire families have disappeared in the sand.”

“Ambulance and civil defense crews were mobilized to the site, and there is talk of a large number of killed and wounded,” he said.

Israeli strikes on Gaza ‘humanitarian area’

Dozens killed after missiles struck the Israeli declared “humanitarian zone” on Monday night, according to Gaza Civil Defense. The Israel Defense Forces said that it was targeting a command-and-control center, but Hamas has denied it had placed fighters in the area.

CNN footage from the aftermath showed emergency crews wearing bright orange vests and scouring dense, blown-out debris for survivors. Rescue personnel could be seen hauling large pieces of barbed wire and dusty mattresses in the dark.

The IDF has accused Hamas and other militant groups in the Gaza Strip of continuing to “systematically abuse civilian and humanitarian infrastructure, including the designated Humanitarian Area, to carry out terrorist activity against the State of Israel and IDF troops.”

Israel has previously struck Al-Mawasi in its pursuit for Hamas commanders and previous strikes have caused significant civilian collateral casualties.

In mid-July, a strike aimed at Hamas’ military chief Mohammed Deif killed at least 90 Palestinians.

The following month, Israel said its intelligence community had confirmed that Deif, one of the reported masterminds of the October 7 attacks, was killed in that attack.

Israel says it has killed or captured half of Hamas’s commanders and more than 14,000 combatants since the war began. However, there are clear signs of the group’s resurgence in parts of the strip previously cleared by Israeli forces, who devastated large swathes of the area in the process.

Surrounded by fire ‘from every side’

CNN footage from Nasser Hospital in Khan Younis on Tuesday showed men and boys standing in congregation to perform Islamic funeral prayers for the deceased. Mourners carried the dead, including children, in white shrouds as women wailed at the steps of the hospital.

“People thought they were asleep safely. Suddenly we woke up to the sounds of explosions, and fires were surrounding us from every side. We didn’t know where the strike hit, where the remains are, or where the blood is. Everything was scattered,” Mahmoud Al Nims, a resident, told CNN.

The Israeli military has placed nearly 86% of the Gaza Strip under evacuation orders, according to the UN. At least 1.9 million people have been displaced.

Another Palestinian, Taghreed Abu Assi, said: “They (Israel) told us to go to Mawasi and we did, and they strike us. We have been displaced a hundred times.”

CNN’s Abeer Salman, Eyad Kourdi and Antoinette Radford contributed reporting. Mohammad Al-Sawalhi and Tareq El Helou reported from Gaza.