Samarra Mosque Attack Inside Job

Sure looks that way.

Authorities have evidence that Wednesday's bombing of Al-Askariya Mosque in Samarra was an inside job, and 15 members of the Iraqi security forces have been arrested, a U.S. military official said.

Two minarets were destroyed at the revered Shiite shrine, the military said, in a repeat of the 2006 bombing that sparked Iraq's current wave of deadly sectarian violence. There was no immediate word on casualties in the city north of Baghdad.

The U.S. military official, Maj. Gen. Benjamin Mixon, told CNN's Karl Penhaul that he believes members of the Iraqi security forces who were guarding the site either assisted or directly took part in helping al Qaeda insurgents place and detonate explosives at the mosque's minarets.

"He told me there was no evidence at all that this was an attack using mortars or anything of the like and said, in his words, that this was an inside job," Penhaul, who's embedded with U.S. troops in Baquba, told CNN's "American Morning."

Mixon said an additional Iraqi army brigade will be sent to Samarra. So far, there have been no reports of sectarian clashes in the city.

A U.S. military spokesman, who would not comment on specific operations, said American forces "continue to conduct the operations we do normally."