WASHINGTON – The Senate will hold hearings into charges that Marines slaughtered up to two dozen Iraqis in a fit of rage, an influential Republican said Sunday.

The military is already investigating the incident in which at least 15 civilians – and as many as 24 – were killed by Marines hunting a roadside bomber on Nov. 19 in Haditha, 140 miles northwest of Baghdad, officials say.

The Marines involved could face charges up to murder.

“I can assure the American public this morning, as chairman of the Armed Services Committee, I’ll do exactly what we did with Abu Ghraib,” Sen. John Warner, R-Va., told ABC’s “This Week.”

“Those people were before our committee … giving the explanation in full.”

Rep. Jack Murtha, D-Pa., a decorated veteran who has become a leading critic of the Iraq war, told ABC the incident is “worse than Abu Ghraib” prison abuse scandal, in part because it was covered up.

The military probe of the killings apparently was not launched until after Time magazine reported them in March.

“There is this serious question, however, of what happened and when it happened and what was the immediate reaction of the senior officers in the Marine Corps,” Warner said.

Lawmakers briefed on the probe have confirmed the broad outlines of the shootings by the 3rd Battalion, 1st Marine Regiment.

“An IED (improvised explosive device) exploded. It killed one Marine,” Murtha said. “And then a taxi drives up. When the taxi comes up, there’s four or five people in it. And they (the Marines) shoot those four or five people, unarmed.

“And then, they go on a rampage throughout the houses and kill people,” said Murtha. “One woman … was bending over a child, pleading for mercy, and they shot her in cold blood.”

Warner, a former Marine, said he would begin hearings after Marine investigators and the Central Command, which covers Iraq, finish their probes.

The military is also investigating an April 26 incident near the town of Hamandiyah involving the 3rd Battalion’s 5th Regiment. Marines there allegedly killed an innocent man, then tried to make him look like an insurgent.