Iran’s supreme leader awarded valor medals on Sunday to Iranian Republican Guard commanders involved in the detention of 10 U.S. Navy sailors at gunpoint last month, a move that could reignite anger about the incident among some U.S. politicians and defense officials.

Photographs of Ayatollah Ali Khamenei awarding the Order of Fat’h medal were released on the supreme leader’s multiple Twitter accounts. One tweet called the Americans detained “intruding U.S. marines,” although all 10 were members of the U.S. Navy.

Sen. John McCain (R-Ariz.), chairman of the Senate Armed Services Committee, said in a statement Monday that the Americans were “mistreated and humiliated” by the Iranians, and noted the the Ayatollah had pinned the Order of Fat’h medal on those involved. Iranian state-run media reported that the head of the Revolutionary Guards and four commanders involved in the seizure of two Navy boats received the awards, which signify victory. The English-language Tehran Times called it a “medal of conquest.”

The pinning comes as U.S. officials continue to grapple with how to characterize what occurred last month. A preliminary investigation conducted by the U.S. Navy found that the sailors, traveling in riverine command boats, were detained Jan. 12 after “mis-navigating” into Iranian waters near Farsi Island, which is home to a highly sensitive Iranian military base.

[Pentagon releases preliminary investigation details of Iran detaining U.S. sailors]

The U.S. sailors were released the following morning by the Iranians. The Iranians later released photographs and videos of the U.S. sailors being detained at gunpoint, and later being fed. One sailor also appears in a video released by Iran saying that the incident was the fault of the Americans and that “Iranian behavior was fantastic while we were here.”

Defense Secretary Ashton B. Carter declined last week to comment on whether he thought the detention had broken international law. But he said he was “very, very angry” about it, showing emotion in a way that he did not in the initial days following the incident. The U.S. Navy would not have acted in the same way, he said.

“I said that before that for me as secretary of defense — I think it’s probably true of everybody in the department — to see our guys in that situation on Iranian TV, that’s really not okay,” Carter said.

[How intense diplomacy between Kerry and Iranian counterpart helped lead to the release of U.S. sailors]

McCain said on Monday that the Obama administration “has still failed to condemn Iran’s behavior for what it was: a violation of international law and centuries of maritime tradition.” The Ayatollah, McCain said, has made his views clear on how American troops should be treated.

“It’s time for the the President and other Administration officials who have incredibly praised Iranian behavior and downplayed the incident to clarify the position of the United States, confidently affirm basic principles of international, and protect our men and women in uniform,” McCain’s statement said.

On Friday, Iran also released a video showing an Iranian drone flying over what appears to be the USS Harry S. Truman, an aircraft carrier in the Persian Gulf. The U.S. Navy said it could not confirm if the video was authentic, but confirmed that an Iranian drone flew over the Truman on Jan. 12, the same day the sailors were detained, after U.S. Navy personnel in a helicopter determined that the craft was unarmed and not a threat.

This still image made from video broadcast on Iranian State television on Friday, Jan. 29, 2016, shows what purports to be drone footage of a U.S. aircraft carrier. (Iranian State Television via AP)