NATO said it and Afghan authorities were investigating whether an alliance airstrike during an operation Friday to rescue two missing American paratroopers had caused casualties. It said it could not confirm whether the base had been hit.

The alliance said reports indicated a total of seven Afghan security forces personnel and one Afghan civilian interpreter had been killed. It added that five U.S. and 15 Afghan soldiers, two policemen and an Afghan civilian interpreter had been wounded in several hours of fighting against insurgents during the search for the missing paratroopers.

The two disappeared on Wednesday while trying to recover supplies that had been airdropped and had fallen into a river, NATO said in a statement. The search was continuing Saturday.

"We are saddened by the loss of life and injuries sustained during this very important mission," U.S. Navy Capt. Jane Campbell, spokeswoman for the NATO forces, said in the statement.

Defense Ministry spokesman Gen. Mohammad Zahir Azimi said an Afghan army commando unit, district police members and foreign forces were in the base in the Bala Marghab district at the time of the airstrike Friday afternoon. Roauf Ahmadi, a spokesman for the western regional police commander, said the airstrike also wounded 15 Afghan soldiers and one policeman.

The Defense Ministry said the Afghan soldiers and policemen were killed "during an air attack by NATO forces in Badghis province."

Separately, the deputy governor of the southern province of Zabul, Ali Khail, said NATO forces raided an Afghan Red Crescent office in the city of Qalat early Saturday, killing a security guard and arresting three local Red Crescent employees.

NATO issued a statement saying coalition forces killed a militant and arrested "a few" suspected militants, including someone who was helping insurgents transport weapons and bomb-making materials to the area.

Red Crescent spokesman Walid Akbar confirmed that international forces had raided the office, but said he had not received any reports of deaths.

Akbar said his organization was negotiating with provincial authorities for the release of the three arrested men, whom he identified as a driver, a communications officer and a guest.

"We are a neutral organization. We help both parties. We help the victims of the war," he said.

According to the NATO statement, alliance forces and Afghan police had targeted a compound "which credible intelligence reported as a location known historically to be used by Taliban commanders."

It said the joint forces came under fire from inside the compound when the police chief in the operation called for those inside to come out. One man was killed when the forces returned fire, it said.

One of those arrested identified himself as a Taliban "facilitator," the statement said, adding that he was responsible for financial support and transporting bomb material and weapons into the area.