An American airstrike in Afghanistan's rugged eastern mountains killed 17 civilians, including women and children, an Afghan official said Monday. The U.S. military confirmed civilian deaths but said the numbers were unclear.

An initial airstrike destroyed a house, and as villagers gathered to look at the damage, a U.S. warplane dropped a second bomb on the same target, Kunar provincial Gov. Asadullah Wafa (search) told The Associated Press.

The airstrike came Friday in the same province where a U.S. transport helicopter was downed last Tuesday in the deadliest single blow to American forces since they ousted the Taliban (search) in 2001.

An unprecedented spate of rebel attacks across the country have left about 700 people dead and threatened to sabotage three years of progress toward peace. Afghan officials insist the violence will not disrupt landmark legislative elections slated for September.

The U.S. military said the attack was carried out "with precision-guided munitions that resulted in the deaths of an unknown number of enemy terrorists and noncombatants."

"The targeted compound was a known operating base for terrorist attacks in Kunar province (search) as well as a base for a medium-level terrorist leader," it said. "Battle damage assessment is currently ongoing."

The statement added U.S. forces "regret the loss of innocent lives and follow stringent rules of engagement specifically to ensure that noncombatants are safeguarded. However, when enemy forces move their families into the locations where they conduct terrorist operations, they put these innocent civilians at risk."

Wafa said it was unclear who was killed in the initial attack in the tiny village of Chechal. "Maybe some militants were killed, but I don't know," he said. "The 17 people were killed in the second bombing."

Meanwhile, the fate of missing members of a team of four Navy SEALs remained uncertain Monday.

Wafa said a second missing service member had been located in his province, wounded and sheltering with an Afghan family. His information came from Afghan intelligence sources, he said.

But a senior Defense Department official in Washington said a second Navy SEAL had not been found. The official spoke on condition of anonymity because of the sensitivity of ongoing rescue operations.

U.S. military spokesman Lt. Col. Jerry O'Hara declined to comment on the governor's comments, except to say "we hold every hope for those who are still missing."

The serviceman rescued on Saturday had taken shelter in an Afghan village elder's home in the province before American forces were notified of his location and picked him up, Wafa said.

The team was reported missing last Tuesday in Kunar. A rescue effort the same day ended in tragedy when the transport helicopter seeking to extract the team was shot down, killing 16 troops aboard.

The BBC, quoting senior U.S. military sources, reported that two of the missing service members were dead and the whereabouts of the fourth remained unclear.

A purported Taliban spokesman, Mullah Latif Hakimi, claimed last week that militants had captured one team member. He said the "high-ranking American" was caught in the area where the helicopter went down.

Hakimi, who also claimed insurgents shot down the helicopter, often calls news organizations to take responsibility for attacks, and the information frequently proves exaggerated or untrue. His exact tie to the Taliban leadership is unclear.

U.S. officials said they had no evidence indicating any service members had been taken into captivity.

The Navy SEAL rescued from Kunar province was being evaluated Monday, officials said. He was in stable condition and receiving medical treatment at the main U.S. base at Bagram. No other information was released.

In a separate development, a joint United Nations-Afghan government electoral commission condemned Sunday's killing of a senior pro-government cleric, Mohammed Nabi Misbah, in the southern city of Kandahar.

Misbah had been working for the commission ahead of the elections, said Bronwyn Curran, an organization spokeswoman. Police have blamed the Taliban for the attack.