Medics look on as an excavator digs through rubble in the search for bodies Monday at the site of Saudi-led airstrikes in Dhamar, Yemen. (Mohamed Al-Sayaghi/Reuters)

A group of Republican and Democratic lawmakers is making a new push to end the Saudi-led bombing campaign in Yemen amid intensifying criticism of the air war following an attack on a rebel-run prison that may have killed more than 100 people Sunday.

The lawmakers’ goal is to prohibit U.S. logistical support for the coalition’s airstrikes through an amendment to the annual defense policy bill, a move that they hope would effectively ground the air campaign by banning the U.S. provision of spare parts that Saudi Arabia needs to maintain its planes. The measure would also restrict certain forms of intelligence-sharing.

The amendment, first presented by Democratic Rep. Ro Khanna of California, already passed in the House’s version of the defense authorization, and now members of both chambers are pressing their colleagues not to remove it during conference negotiations with the Senate.

“We strongly urge you to include the House provision that prohibits military support for the Saudi-led coalition’s war” against the Houthi rebels in Yemen, the lawmakers said in a letter obtained by The Washington Post that was signed by Sens. Bernie Sanders (I-Vt.) and Elizabeth Warren (D-Mass.), as well as Republican Sens. Rand Paul (Ky.) and Mike Lee (Utah), and Reps. Adam B. Schiff (D-Calif.), Mark Pocan (D-Wis.), Matt Gaetz (R-Fla.), and dozens of others.

“Inclusion of this amendment would ensure that our men and women in uniform are not involved in a war which has never been authorized by Congress, and continues to undermine rather than advance U.S. national security interests,” the lawmakers wrote.

The letter is addressed to the top Republicans and Democrats on the armed services committees, who will negotiate a range of disparities between the House and Senate versions of the bill, including other Democratic amendments to reverse President Trump’s ban on transgender troops and prohibit spending military money on military parades and Trump’s properties.

The lawmakers’ appeal comes as the Yemen conflict drags on in its fifth year, with the civilian death toll rising and feuding among factions allied with key U.S. partners complicating prospects for peace.

The Trump administration has urged a swift halt to clashes in southern Yemen between forces affiliated with the internationally recognized government, which is closely linked to Saudi Arabia, and forces backed by the kingdom’s chief partner in Yemen, the United Arab Emirates.

U.S. officials have long called for a political solution to end the war, but the Trump administration also has increasingly framed the conflict in terms of a larger regional standoff with Iran.

Mounting congressional frustration with Saudi Arabia — fueled partly by the killing of journalist Jamal Khashoggi at the Saudi Consulate in Istanbul last year — has resulted in a series of bipartisan legislative steps over the past year but has failed to end U.S. support for Saudi Arabia in the war.

Pentagon officials argue that a decision last year to halt aerial refueling of Saudi jets has limited military support. But the United States continues to share certain intelligence on Yemen with Saudi Arabia, even as it moves ahead with massive arms sales to the kingdom.

The House-passed version would also restrict U.S. maintenance of Saudi flight operations.

Saudi officials have said they would prefer to press ahead with Washington as its primary military partner but that they can rely on other nations if needed.

Pentagon officials see Saudi Arabia as an important regional partner and a counterweight to Iran. But the stalemated conflict in Yemen, which has killed tens of thousands of people and thrust millions into near-famine conditions, has prompted widespread humanitarian criticism of the United States and Saudi Arabia.

On Monday, Yemeni medical workers pulled bodies from the bombed-out detention center run by the rebels that was hit Sunday. Dozens of people were wounded and more than 100 people were “presumed killed” in the attack, the International Committee of the Red Cross said.

Saudi officials said the facility was being used as an arms deport, and a spokesman for the Saudi-led coalition, Col. Turki al-Maliki, called it a “legitimate military target.”

“Now we must use Congress’s power of the purse to block every nickel of taxpayer money from going to assist the Saudi dictatorship as it bombs and starves civilians in Yemen,” Sanders said in a statement.

In a scathing report on the conflict, the United Nations said Tuesday that the United States, Britain and France may be complicit in potential war crimes by arming and backing the coalition.

A team of investigators commissioned by the U.N. Human Rights Council found that all parties in the conflict had perpetrated possible war crimes through airstrikes, shelling, snipers and land mines, as well as arbitrary killings, torture and other abuses.

The report also accused Iran of helping to perpetrate war crimes through its support for the rebels.

Sudarsan Raghavan in Cairo contributed to this report.