A UN aid agency for Palestinian refugees said Tuesday that a stockpile of Hamas rockets was found in one of UNRWA’s Gaza schools — for the third time since the onset of Operation Protective Edge.

The incident, however, was not publicized by UNRWA on its website or official Twitter feed, or that of its spokesperson.

In its press release, UNRWA’s spokesperson said that the discovery was made during a routine inspection of the school, “which was closed for the summer and not being used as a shelter.”

“All the relevant parties have been notified,” UNRWA said, without elaborating which parties. Hamas, the terror group that controls the Gaza Strip, has launched over 2,000 of rockets at Israel in the past month.

“We condemn the group or groups who endangered civilians by placing these munitions in our school,” said UNRWA Spokesperson, Chris Gunness. “This is yet another flagrant violation of the neutrality of our premises. We call on all the warring parties to respect the inviolability of UN property.”

Despite announcing the discovery, UNRWA could not send a UN munitions expert to disarm and remove the weapons “because of fighting in the vicinity,” it said in a statement. “But we hope to do as soon as the security conditions allow.”

It was not clear from the statement where the school was, how many rockets Hamas or one of the other Palestinian terror groups stored at the UN facility, or where the weapons are now.

Tuesday’s incident was the third instance in which Palestinian armaments were found in UN facilities in the Gaza Strip. On July 22, the UN agency found rockets stockpiled in another school which “is situated between two other UNRWA schools that currently each accommodate 1,500 internally displaced persons.”

A week before that, UNRWA found some 20 rockets in a school under its auspices, also during a standard inspection. A spokesperson for UNRWA said the organization gave the rockets to “local authorities,” which answer to the Hamas-backed unity government led by Palestinian Authority President Mahmoud Abbas. “According to longstanding UN practice in UN humanitarian operations worldwide, incidents involving unexploded ordnance that could endanger beneficiaries and staff are referred to the local authorities,” Gunness told The Times of Israel.

In Jerusalem, officials charged that the weaponry was returned to Hamas. “The rockets were passed on to the government authorities in Gaza, which is Hamas. In other words, UNRWA handed to Hamas rockets that could well be shot at Israel,” a senior Israeli official told The Times of Israel.

Raphael Ahren contributed to this report.