Defense Secretary Donald H. Rumsfeld said Saturday that he wanted U.S. commanders in Afghanistan to expedite their investigation of allegations that U.S. soldiers burned the remains of Taliban fighters they had killed, and then used the scene for propaganda purposes.

Investigators should proceed with a "sense of urgency," Rumsfeld said, in light of the potential for damage to U.S. interests from a backlash in the Muslim world.

Rumsfeld said Pentagon lawyers had advised him to be careful about what he says because his remarks about specifics of the case could complicate the proceedings.

Rumsfeld made it clear that he was worried by the allegations, whatever their merit.

"The reality is that charges of that type are harmful," he said. "They don't represent the overwhelmingly positive behavior of the men and women in uniform who do such a wonderful job. It's always disappointing when there are charges like that. It's particularly disappointing when they're true. That needs to be determined, but one hates to see the adverse effect of it, if it is true."

The defense secretary cited as an example the riots in Afghanistan this year that some people linked to anger over reports that a copy of the Koran was flushed down a toilet by U.S. military personnel in the detention center at Guantanamo Bay, Cuba. U.S. investigators said they found no evidence of such an incident, but confirmed other examples of Koran abuse.

Rumsfeld was in the Lithuanian capital to attend meetings of NATO defense ministers beginning Sunday.