A top U.S. commander in Iraq has concluded that some senior Marine officers failed to investigate fully the killings of as many as 24 Iraqi civilians in Haditha last November.

Lieutenant-General Peter Chiarelli (file photo)

Military officials say Lieutenant-General Peter Chiarelli, head of ground forces in Iraq, concluded that senior officers failed to look into inconsistencies in the initial reporting of the incident.

The New York Times quotes officials Saturday as saying General Chiarelli recommended unspecified disciplinary action for some officers.

The U.S. military said Friday General Chiarelli forwarded his findings and recommendations to General George Casey, the top commander of coalition forces in Iraq.

A separate investigation is under way into the killings themselves.

U.S. Marines are accused of killing the civilians after a roadside bomb killed a fellow Marine. Official reports initially said the civilians were killed by the roadside bomb.

Separately, the U.S. military says insurgents killed three American soldiers Saturday in al-Anbar province.

In Iraq Friday, at least 17 people died in a series of bombings and mortar attacks against mosques across the country.

Iraqi troops killed as many as 40 insurgents during a raid on Shi'ite fighters in Baghdad that also resulted in the capture of a high-level insurgent.

Some information for this report was provided by Reuters.