Congressional critics of the Saudi-led military campaign against Yemeni rebels are demanding the White House pull its support for Riyadh following an alleged weekend airstrike that killed at least 140 funeral mourners in Sanaa.

The Obama administration has already said it is considering ratcheting back its aid for Saudi Arabia — a rare step that all but certainly will inflame America’s most powerful ally in the Arab world. But lawmakers said they remain unappeased by the White House threat in the face of the growing civilian death toll in Yemen’s nearly two-year war.

“The continuing civilian carnage caused by the Saudi Arabia-led military coalition in Yemen appears to be war crimes,” Rep. Ted Lieu (D-Calif.) told Foreign Policy on Monday. Lieu, who earlier led an unsuccessful House effort to block a $1.15 billion arms deal to Saudi Arabia, demanded the U.S. immediately cease support to the Saudi coalition while the Obama administration reviews options to permanently pull American assistance.

On Sunday, Sen. Chris Murphy (D-Conn.) said, “we are past the point of strongly worded statements.”

“The administration should pull U.S. support for the Saudi-led war in Yemen,” said Murphy, a leading critic of U.S. support for the oil-rich monarchy.

Officials at the White House and State Department declined Monday to specify which types of U.S. support to the Saudi coalition could be withheld, or if Washington was still providing targeting information to the coalition. The U.S. currently provides refueling and logistical support to Riyadh’s air force.

In a Saturday statement following the funeral attack, White House spokesman Ned Price said: “We have initiated an immediate review of our already significantly reduced support to the Saudi-led coalition and are prepared to adjust our support so as to better align with U.S. principles, values, and interests.”

Saudi Arabia initially denied any involvement in the strike in the Yemeni capital of Sanaa, but on Sunday announced an investigation into the “regrettable and painful bombing.” The United Nations and the European Union have also condemned the attack, which injured at least 525 people when Yemenis had gathered to mourn the death of the father of Interior Minister Jalal al-Ruwaishan, an Houthi ally.

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Since March 2015, Riyadh has waged war against the Houthi rebels who have taken control over large swaths of Yemen.

U.S. support for Saudi Arabia in the ongoing conflict has also caused a rift inside the Obama administration, according to emails and interviews obtained by Reuters. The correspondence, which date back to summer 2015, show officials at the Pentagon and the State Department’s Bureau of Near East Affairs seeking to maintain warm relations with Saudi Arabia, especially amid heightened anxiety over the nuclear deal with Iran.

But officials at the State Department’s Office of the Legal Adviser warned that the U.S. could be implicated in war crimes for its continued support of the air campaign — a fact Lieu seized on Monday.

“This latest news on the humanitarian crisis in Yemen — that State Department lawyers knew the U.S. could be liable for war crimes — is deeply troubling,” he told FP.

The ramifications of America’s involvement in the conflict may not just be legal, either. On Sunday, two missiles fired from a Houthi-controlled area of Yemen targeted a U.S. Navy destroyer. Though the missiles missed the mark, it was believed to be the first instance in which Houthis attempted to attack American ships since the war began.

Riyadh has promised in coming weeks to investigate the funeral bombing and “will seek advice from the USA to help,” according to a Sunday statement from the kingdom. A State Department official declined to say who from the United States would assist in the effort, and noted that while the U.S. is not a formal part of the investigation, “we are consulting.”

On Sunday, Secretary of State John Kerry spoke to Saudi Deputy Crown Prince Mohammad bin Salman and Foreign Minister Adel al Jubeir, according to State Department spokesman Mark Toner.

“Secretary Kerry reiterated our deep concern about the October 8 attack on the funeral hall in Yemen that resulted in a large number of civilian casualties,” said Toner. “He welcomed the deputy crown prince’s commitment to launch a thorough and immediate investigation of the strike and urged him to take urgent steps to ensure such an incident does not happen again.”

At the same time, Kerry described as “legitimate” Riyadh’s demand that Houthis remove their weapons from Saudi Arabia’s border.

On Sunday, the Saudi coalition said it intercepted two ballistic missiles from the Houthis, including one aimed at the Saudi city of Taif, near Mecca.