YERUSHALAYIM (Hamodia Staff) – Several U.S. senators are calling for an investigation into the role of the United Nations Relief and Works Agency (UNRWA) during the war in Gaza, The Jerusalem Post reported on Wednesday.

Accusing UNRWA of collaborating with Hamas, Senate Foreign Relations Committee members Mark Kirk (R-Ill.), Ben Cardin (D-Md.) and Marco Rubio (R-Fla.) wrote a letter this week to U.S. Secretary of State John Kerry saying that the ostensibly neutral U.N. agency has been biased and called its behavior “troubling.”

Early in the fighting in Gaza, UNRWA officials publicly alleged Israeli violations of international humanitarian law. It was also caught three times with terrorist rockets stashed in schools it runs, though the agency disavowed prior knowledge of the weapons being on their property.

“UNRWA claimed they were turned over [the rockets] to the ‘local authorities’ or have gone missing,” the Senate letter reads. “We fear that this means these rockets may have found their way back into Hamas’ hands.”

While the letter falls short of recommending a cut in U.S. aid to UNRWA – $294 million in 2013 and a total of $5 billion since 1950 – the senators wrote that the American taxpayers “deserve to know if UNRWA is fulfilling its mission or taking sides in this tragic conflict.”

A State Department spokesman said that the U.N. is taking “proactive steps to address this problem,” including deploying munitions experts to the strip in search of more weapons caches.

“The international community cannot accept a situation where the United Nations – its facilities, staff and those it is protecting – are used as shields for… terrorist groups,” State Department spokesman Edgar Vasquez said. “We remain in intensive consultations with U.N. leadership…”

Foreign Minister Avigdor Lieberman said on Wednesday that Israel should not cooperate with the U.N. Human Rights Council (UNHRC) probe into possible war crimes in Gaza, noting the anti-Israel bias of its chairman, Prof. William Schabas, who has called for Prime Minister Binyamin Netanyahu to stand trial for war crimes.