GAZA — At least 40 people have been killed in an overnight Israeli strike on a humanitarian zone created to shelter displaced people in southern Gaza, according to local rescue officials, in what Israel has said was an operation targeting Hamas fighters in the area.

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.

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 and paucity of light.

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.

Hamas denied it had placed fighters in the area.

The strike hit Al-Mawasi, a coastal region in Khan Younis where tens of thousands of displaced Palestinians have fled to, many living in tents in an area with sparse infrastructure, scant access to shelter or life-saving humanitarian aid.

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.

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

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

Gaza Civil Defense spokesman Mahmoud 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.”

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

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

Video circulating on social media, and shared by Hamas media outlet Al Aqsa TV, showed Gaza Civil Defense members digging in the sand as they search for missing people. Clothes and shoes can be seen scattered across the area. CNN has been unable to independently verify the footage.

An Associated Press camera operator on scene saw three large craters and people pulling body parts from the sand, including what appeared to be a human leg.

“The people were buried in the sand. They were retrieved as body parts,” Attaf al-Shaar, who was displaced from the southern city of Rafah, told the AP.

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. — CNN