Amnesty International says satellite footage and witness accounts offer damning new evidence that Nigeria's military killed hundreds of minority Shiite Muslims late last year.

The Dec. 12-14 massacre in the northern town of Zaria is currently the subject of a government inquiry.

The Amnesty report cites witnesses saying some victims were burned alive and bodies were disposed of in mass graves.

An official from Kaduna state testified April 11 that soldiers secretly buried 347 victims, though the Shiites put the toll closer to 1,000.

The military said the raids came after Shiites attempted to assassinate Nigeria's army chief, which the Shiite Islamic Movement in Nigeria denies.

Amnesty on Friday urged Nigeria's military to "come clean."

Army spokesman Col. Sani Kukasheka Usman said Amnesty's report was "hasty" and lacked credibility.