Washington ? An initial U.S. military probe supports allegations that American Marines deliberately shot 24 Iraqi civilians in Haditha in November, a Pentagon official said Wednesday.

The Marine Corps and Navy prosecutors are now reviewing the evidence to determine whether to recommend criminal charges. That decision may be weeks away, and the lawyers may ask investigators to probe further, two officials said.

They discussed the matter on condition they not be identified because the case – among the most sensational of several involving Iraqi civilian deaths – has not yet produced charges.

“It’s fair to say that the majority of the work has been done,” said a third official, Ed Buice, spokesman for the Naval Criminal Investigation Service that is leading the probe. “But it’s impossible to predict how much longer the investigation will take. It is very much open and ongoing.”

The case is open because prosecutors and officers in the chain of command of the Marines being investigated may consult with the naval investigation service even after any charges are brought.

A decision on whether to press charges ultimately will be made by the commander of the Marines’ parent unit, the 1st Marine Expeditionary Force at Camp Pendleton, Calif. That currently is Lt. Gen. John Sattler, but he is to move to a Pentagon assignment soon. His successor will be Lt. Gen. James Mattis.

Investigators conducted a wide range of interviews with Marines in Iraq and with Iraqis in Haditha, but they failed to obtain permission to exhume the bodies of the 24 who were killed, two officials said. Nonetheless the probe did collect evidence from the Marines and from the scene of the killings.

The case is one of several involving allegations of unjustified killings of Iraqi civilians that have emerged this year, damaging the U.S. image abroad and triggering calls by some Iraqi leaders to end the arrangement under which U.S. troops are immune from prosecution by Iraqi authorities.

The Marines initially reported after the Nov. 19, killings at Haditha that 15 Iraqi civilians had been killed by a makeshift roadside bomb and in crossfire between Marines and insurgent attackers. Based on accounts from survivors and human rights groups, Time magazine reported in March that the killings were deliberate acts by the Marines.

A criminal investigation was then ordered by the top Marine commander in Iraq, Maj. Gen. Richard Zilmer.

A parallel investigation is examining whether officers in the Marines’ chain of command tried to cover up the events. That probe, which has not been made public, faults some officers for failing to pursue discrepancies in the initial reports about what happened in Haditha and for not launching an early investigation.

When asked about the matter at a news conference Wednesday, Marine Gen. Peter Pace, chairman of the Joint Chiefs of Staff, said the cover-up probe’s report was 3,000-4,000 pages long and being reviewed by Army Gen. George Casey, the top commander in Iraq.

Regarding the criminal investigation, Pace described it as “ongoing” and said it would remain so until military authorities have reviewed its results as well as the findings and recommendations of the cover-up probe, “to make sure that every single possible cross-thread has been looked at.”

Public attention on the Haditha case grew after Rep. John Murtha, D-Pa., a former Marine, asserted on May 17 that he had learned from Marine Corps officials that innocent Iraqis had been killed “in cold blood.”

Attorneys for Staff Sgt. Frank D. Wuterich, one of the Marines under investigation, argued in a lawsuit filed Wednesday in federal court that Murtha falsely accused Wuterich of murder and war crimes. The lawsuit maintains that Pentagon officials “who have briefed or leaked information to Mr. Murtha deliberately provided him with inaccurate and false information” and that the congressman subsequently “has made repeated statements … that are defamatory.”

Murtha said Wednesday he does not blame Wuterich for “lashing out.”

“When I spoke up about Haditha, my intention was to draw attention to the horrendous pressure put on our troops in Iraq and to the cover-up of the incident,” Murtha said.

Among the other recent cases of alleged deliberate killings of Iraqi civilians, seven Marines and one Navy corpsman have been charged with premeditated murder and other criminal acts in connection with the killing of an Iraqi man in Hamdania on April 26. Also, five soldiers and a former soldier have been charged in the alleged March 12 rape-slaying of an Iraqi teenager and the killings of her relatives in Mahmoudiya.