Victims and relatives of people killed or injured in attacks by Hamas and Hezbollah have sued the United Nations agency dedicated to Palestinians, accusing it of aiding the armed groups and fueling terrorism.

The lawsuit was filed Thursday in federal court in Washington, D.C., by U.S. citizens living in Israel and the United States and their family members. A similar case has been playing out since last year in federal court in New York.

Both suits are attempting to hold the U.N. Relief and Works Agency, known as UNRWA, responsible in some measure for violent acts by Hamas in the Gaza Strip and Hezbollah in Lebanon, groups dedicated to the destruction of Israel that have been designated terrorist organizations by the United States. The plaintiffs are seeking unspecified monetary damages, both compensatory and punitive.

Israel has long maintained that UNRWA has been infiltrated by militants and is biased against Israel in the war in Gaza, an accusation U.N. officials have denied. The agency has been at the center of controversy during the conflict, which was set off by the Hamas-led attack on Israel on Oct. 7, 2023.

In the New York case, lawyers for the U.N. agency have argued that the organization is exempt from such suits because it has diplomatic immunity. The Biden administration supported that position, but in April, lawyers in President Donald Trump’s Justice Department reversed the government’s stance, paving the way for the latest lawsuit.

Some analysts say the Justice Department’s new position could open the door not only to more civil cases seeking damages from the agency, but to the Treasury Department’s imposing sanctions on it.

The complaint argues, among other things, that UNRWA has violated anti-terrorism laws by providing direct and indirect support to Hamas and Hezbollah. It also accuses UNRWA USA, a nonprofit organization that raises money for the agency, of helping with the effort by soliciting donations.

Representatives for UNRWA and UNRWA USA did not respond to requests for comment. Lawyers representing the plaintiffs also did not comment.

In the past, UNRWA officials have consistently denied that the agency’s Gaza staff is full of Hamas operatives, though they have also said it is impossible to operate in Gaza without some engagement with Hamas, which has governed the enclave since 2007. Workers who have been accused of having ties to Hamas are investigated. UNRWA says it takes those accusations seriously.

Israel has accused some agency employees of participating in the 2023 attack, and nine workers were ultimately fired for possible involvement. The Israeli military has said that UNRWA fails to prevent Hamas from storing weapons in civilian settings or building tunnels under agency infrastructure in Gaza.