The U.S. military should end its refueling support of Saudi Arabia warplanes in Yemen no matter where an investigation into the kingdom’s suspected murder of a Washington-based journalist leads, Sen. Jack Reed, D-R.I., said Wednesday.

Reed, the top Democrat on the Armed Services Committee, said the support has not allowed the U.S. to influence the Saudis as they wage a four-year-old war and face allegations of targeting civilians amid a crushing humanitarian crisis in the Middle Eastern country.

The military’s support of aerial refueling, logistics, and munitions to Saudi Arabia and reports of airstrikes killing scores of civilians was stoking bipartisan outrage on Capitol Hill before Washington Post contributor Jamal Khashoggi disappeared after entering a Saudi consulate and was allegedly killed and dismembered, according to Turkish authorities.

“With respect to Yemen regardless what is determined about Khashoggi, I think we should terminate the aerial refueling,” Reed said during a breakfast with defense reporters. “I don’t think it provides any controls over their behavior and I think what it does is involve us in activities and actions that we can’t control and have no knowledge of, and that’s not a good position for us to be.”

Defense Secretary Jim Mattis had urged Congress not to limit the support, saying the close relationship allows it to help the Saudis avoid strikes on civilian targets.

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In August, the Saudis were accused of bombing a school bus and killing 40 children, an incident that Reed said has still not been fully explained.

The Senate narrowly defeated a measure earlier this year calling to sever U.S. military support of Saudi Arabia and the United Arab Emirates as they fight rebels aligned with Iran, a top adversary of the Trump administration.

Sen. Bernie Sanders, I-Vt., a sponsor of the resolution, said he is prepared to reintroduce the bill in the Senate, where it could get more support as the Khashoggi incident ratchets up already deep concerns about the kingdom’s activities.

“It appears that this was a grotesque and obscene act by the elements within Saudi Arabia,” Reed said of Khashoggi’s disappearance. “So the first step, I think, is to determine exactly what happened. That, I believe, requires a thorough international investigation not something that the Saudis will do.”