Three IDF soldiers were killed Wednesday morning in Gaza in an explosion at a booby-trapped UNRWA health clinic that housed a tunnel entry shaft, the IDF’s Gaza Division commander, Brig. Gen. Micky Edelstein, said in a briefing.

After describing certain precautionary measures, Edelstein said, “And then we enter with our people, and they [the militants], from the very same terror tunnel, they blow up half the clinic on our troops.”

“They blow [up] the UNRWA clinic on our troops.”

UNRWA did not immediately respond to a request for comment.

However, the Coordinator of Government Activities in the Territories, the military unit that implements government policies in the Palestinian areas, later said that the clinic in Abu Daka, outside Khan Younis, was last registered as a sensitive location three years ago, “and it hasn’t been since.”

The spokesperson said the site had not been registered then as belonging to UNRWA, leading to speculation that, perhaps, militants stole the sign and tacked it on the door, posting it as a security umbrella under which a tunnel could be dug.

The army named the fallen soldiers as Staff Sgt. Matan Gotlib, 21, of Rishon Lezion, Staff Sgt. Omer Chai, 21, of Savion, and Sgt. Guy Algranati, 20, of Tel Aviv.

The three soldiers, members of the elite Maglan unit, were taking precautionary measures in efforts to limit damage to the structure before eliminating the tunnel, when the explosives detonated in the small building.

The soldiers had sent in sniffing dogs and a small tractor to minimize damage to the structure, but explosives rigged to the building detonated, toppling a section of the building on the soldiers.

Fifteen soldiers were injured. IDF soldiers evacuating the wounded came under fire from Palestinian fighters. All of the fatalities and injured were eventually brought back to Israeli territory.

The deaths brought the toll of IDF soldiers killed since the beginning of Operation Protective Edge to 56.

Edelstein used the alleged clinic as an illustration of the difficulty inherent in fighting an enemy willing to exploit both civilians and non-governmental organizations. “Once you enter such a clinic and you see the UNRWA sigh on it and you know there is a terror tunnel there, you know it’s a very very sensitive building, and you’re thinking of the not-terrorist Palestinians living there all around, and you’re trying not to harm this place,” Edelstein said.

SSgt. Omer Chai (photo credit: Courtesy)

SSgt. Omer Chai (photo credit: Courtesy)

SSgt. Guy Algranati (photo credit: Courtesy)

SSgt. Guy Algranati (photo credit: Courtesy)

Sgt. Matan Gotlib (photo credit: Facebook)

Sgt. Matan Gotlib (photo credit: Facebook)

He said Hamas militants have used more than a thousand IEDs so far, destroying thousands of buildings in the Gaza Strip.

As an example he noted that in sweeps of a single street of 28 buildings Tuesday night, 19 were found to be booby-trapped.

In a briefing about progress in the campaign, IDF Southern Command head Maj. Gen. Sami Turgeman said “many hundreds” of Hamas operatives have been killed and that the IDF has destroyed hundreds of weapons storage facilities, and significantly compromised Hamas’s “terror infrastructure.”

Turgeman said the IDF is “days away” from completing the military goal of destroying all of the tunnels, though the process is complex. Four tunnels have been destroyed in the past 24 hours, he added.

Turgeman revealed that the IDF expanded its operation on Tuesday night, targeting new sites in the north and center of the coastal enclave.

With the amount of concrete Hamas poured into the tunnel project, two hospitals, 20 schools, 20 healthcare centers, and 100 kindergartens could have been built, he said.

Marissa Newman and Stuart Winer contributed to this report.

This article was updated to reflect the new information provided by COGAT, which was not available initially.