A Navy hospital corpsman assigned to Kaneohe Bay is missing after an early Sunday morning altercation at Kelley O’Neil’s bar in Waikiki that involved a Marine companion, the Marine Corps and family said.

Seaman Shaun Palmer is assigned to the 1st Battalion, 3rd Marines at Marine Corps Base Hawaii.

“Please help me find my son,” his mother, Diane, posted on Twitter, adding that her son’s phone is dead and there has been no activity on his credit cards.

The sailor was last seen at Kelley O’Neil’s, she said.

“There are a lot of unknowns, and we’re just hoping that he turns up tonight. We have no reason to think that he wouldn’t,” Marine Corps spokesman Capt. Eric Abrams said Monday evening. “We don’t have information that anything else is in play.”

Palmer was with a Marine who was arrested after a “low-key” altercation, Abrams said. No major injuries were reported and the Marine was later released, he said.

A missing-person report has been filed with the Honolulu Police Department, and Palmer’s command is working closely with local and military officials to find the missing sailor, the Marines said.

Palmer was not scheduled to participate in any Rim of the Pacific exercises, the Corps said.

Mae Dean, a manager at Kelley O’Neil’s, said the altercation happened around closing time at 4 a.m. when everyone was being asked to leave the bar.

She was at work Sunday morning, and one of Palmer’s supervisors came by looking for him, she said.

“From what I understand, we’ve already checked the (video) tapes,” Dean said Monday evening. “I just spoke to the (Naval Criminal Investigative Service), they just left five minutes ago, and there was nothing that we saw on camera, because it was really crowded at the time.”

NCIS “asked to see our cameras, and we complied,” she said. Investigators “didn’t see anything (either),” she said.

Palmer’s mother said her son canceled a Lyft ride at 4:30 a.m. that morning.