Washington ? Ten to 15 people killed in a deadly Jan. 23 commando raid conducted by U.S. special forces in Afghanistan were not al-Qaida or Taliban as first suspected, Defense Secretary Donald H. Rumsfeld said Thursday.

Rumsfeld defended the raid on the two compounds at Hazar Qadam, saying the deaths occurred after U.S. forces defended themselves when they were fired upon.

“Clearly, in retrospect, that’s unfortunate,” Rumsfeld said of the deaths. “On the other hand, one cannot fault the people who fired back in self-defense.”

Previously, the Pentagon had said American forces had determined they captured the wrong people during the deadly raid. Those people were released.

Asked if the raid was a mistake, Rumsfeld said: “It is no mistake at all, if you’re fired on, to fire back. We expect people to defend themselves.”

He noted that Afghans inside the second compound approached by U.S. forces during the raid did not fire back, and were taken into custody. Those people also were later released.

Intelligence information gathered over several weeks by U.S. officials was “persuasive and compelling” in indicating that al-Qaida and Taliban might be inside the compounds, Rumsfeld said. Asked if the intelligence had been in error, Rumsfeld said circumstances on the ground in Afghanistan were difficult.

“It’s untidy. It is not a neat situation where all the good guys are here, and all the bad guys are there,” Rumsfeld said.

He said that to his knowledge, U.S. officials had relied on their own intelligence not that provided by local Afghans to determine that the compound might hold al-Qaida and Taliban.

Rumsfeld, speaking to reporters at a Pentagon briefing, said American forces looking into the incident had determined the individuals killed and captured in the raid were Afghans associated with a local Afghan ruler.

The raid on the two compounds took place about 60 miles north of Kandahar in the Hazar Qadam Valley village of Khas Uruzgan.

Pentagon officials have said previously that the men inside the compound “were not wearing uniforms, were carrying weapons and they fired upon U.S. forces in uniform.” One U.S. soldier suffered a bullet wound in the ankle during the operation.

Local Afghans say some of those killed were anti-Taliban forces loyal to Karzai, and that among those arrested were a police chief, his deputy and members of a district council.

U.S. forces said they found a large cache of weapons. Some Afghans say Taliban renegades were handing over weapons to the new government at the site.

The raid was one among a series that have been carried out by U.S. special forces sometimes in tandem with Afghan forces to extinguish pockets of Taliban and al-Qaida resistance.

Rumsfeld had previously cited three “notable facts” indicating al-Qaida and Taliban might have been in the compounds: the large numbers of weapons, the absence of women and children, and the fact that the U.S. troops were shot at as they breached the compound.