GAZA CITY, Gaza Strip (AP) — The Israeli military says it has discovered tunnels underneath the main headquarters of the U.N. agency for Palestinian refugees in Gaza City, alleging that Hamas militants used the space as an electrical supply room.

The unveiling of the tunnels marked the latest chapter in Israel’s campaign against the embattled agency, which it accuses of collaborating with Hamas.

Recent Israeli allegations that a dozen staff members participated in the Hamas attack on Israel Oct. 7 plunged the agency into a financial crisis, prompting major donor states to suspend their funding as well as twin investigations. The agency says that Israel has also frozen its bank account, embargoed aid shipments and canceled its tax benefits.

It did not prove definitively that Hamas militants operated in the tunnels underneath the UNRWA facility, but it did show that at least a portion of the tunnel ran underneath the facility’s courtyard. The military claimed that the headquarters supplied the tunnels with electricity.

UNRWA Commissioner-General Philippe Lazzarini said the agency had no knowledge of the facility’s underground, but the findings merit an “independent inquiry,” which the agency is unable to perform due to the ongoing war.

The headquarters, on the western edge of Gaza City, are now completely decimated. To locate the tunnel, forces repeated an Israeli tactic used elsewhere in the strip, overturning mounds of red earth to produce a crater-like hole giving way to a small tunnel entrance. The unearthed shaft led to an underground passageway that an Associated Press journalist estimated stretched for at least half a kilometer (quarter of a mile), with at least 10 doors.

At one point, journalists were able to gaze upward from the tunnel, through a hole, and make eye contact with soldiers standing in a courtyard within the UNRWA facility.

Inside one of the UNRWA buildings, journalists saw a room full of computers with wires stretching down into the ground. Soldiers then showed them a room in the underground tunnel where they claimed the wires connected.

That underground room bore a wall of electrical cabinets with multicolored buttons and was lined with dozens of cables. The military claimed the room served as a hub powering tunnel infrastructure in the area.

“Twenty meters above us is the UNRWA headquarters,” said Lt. Col. Ido, whose last name was redacted by the military. “This is the electricity room, you can see all around here. The batteries, the electricity on walls, everything is conducted from here, all the energy for the tunnels which you walked though them are powered from here.”

The military said forces uncovered rifles, ammunition, grenades, and explosives in the facility, claiming it has been used by Hamas militants. Lazzarini said the agency has not revisited the headquarters since staff evacuated Oct. 12, and is unaware of how the facility may have been used.

Israel has found similar primitive quarters in tunnels across Gaza over the course of its 4 month-long campaign in Gaza. The offensive was launched after Hamas militants attacked Israel on Oct. 7, killing some 1,200 people and dragging 250 hostages back to Gaza. Since then, Israeli war planes and ground troops have killed over 27,000 Palestinians in the strip, unleashed a humanitarian catastrophe and wreaked widespread damage.

Leaving the facility, it was nearly impossible to identify one window left fully intact. Bullet holes pockmarked the walls. Shrapnel was everywhere, crumpled-up U.N. vehicles were perched precariously atop building debris. Dogs roamed the area.

BY ARIEL SCHALIT