KABUL, Afghanistan — U.S. forces desperately scoured rugged Afghan mountains yesterday for an elite American military team missing in the same area where a U.S. helicopter was shot down trying to rescue it.

A purported Taliban spokesman claimed militants had captured one of the men.

There was guarded optimism in Washington that some or all four members of the missing Navy SEAL team could be alive.

In an unrelated incident late yesterday, hundreds of Afghan troops raided a Taliban hide-out in the mountains of central Afghanistan and 18 rebels and two soldiers were killed in fierce fighting, a senior Afghan official said today.

Security forces assaulted the rebel camp in Uruzgan province's Charchino district to flush out the insurgents who have been blamed for a spate of kidnappings and killings across the region, said provincial Gov. Jan Mohammed Khan.

The troops were still in the region today searching for about 100 insurgents thought to be there.

Yesterday, a Pentagon official said that "radio transmissions" had given U.S. forces more hope than they had had the previous day that the missing SEALs had survived. He said he was not able to be more specific.

Though the team has been missing since Tuesday, the military had refrained from discussing their situation to prevent the Taliban from setting out in search of them.

The missing status of the military team in the remote eastern mountains worsened the already stinging blow suffered by the U.S. military after 16 troops were killed Tuesday aboard the MH-47 Chinook chopper.

It comes as the United States is scrambling to deal with an insurgency that threatens three years of progress toward peace.

U.S. forces were using "every available asset" to search for the missing men, said Lt. Col. Jerry O'Hara, a U.S. military spokesman.

"Until we find our guys, they are still listed as unaccounted for and everything we've got in that area is oriented on finding the missing men," he said.

The helicopter had been trying to "extract the soldiers" Tuesday when it went into the mountains close to the Pakistani border, O'Hara said.

The Taliban claim to have kidnapped one of the men came from purported spokesman Mullah Latif Hakimi. "One high-ranking American has been captured in fighting in the same area as the helicopter went down," he said.

"I won't give you any more details now."

Reacting to the claim, O'Hara said, "We have no proof or evidence indicating anything other than the soldiers are missing."

Rescuers — struggling against stormy weather, insurgents and the rugged terrain — recovered the remains of the 16 in the downed helicopter and were trying to identify them, the military said. A rocket-propelled grenade apparently hit the chopper.

The loss of the helicopter follows three months of unprecedented fighting that has killed about 477 suspected insurgents, 47 Afghan police and soldiers, 134 civilians and 45 U.S. troops.

In central Afghanistan yesterday, Taliban rebels kidnapped and killed nine Afghan tribal leaders and sent a boy to offer to exchange the bodies for those of dead militants, an official said. The tribal leaders were among 25 people killed in three days of fighting in Uruzgan province — a troubling sign for a nation hit by an upswing in violence as September elections near.

Yesterday, rebels also attacked a Uruzgan police post, and five insurgents and four officers were killed, provincial Gov. Jan Mohammed Khan said.

Only eight months ago, Afghan and U.S. officials were hailing a relatively peaceful presidential election as a sign that the Taliban rebellion was finished.

But remnants of the former Taliban regime have stepped up attacks, and there are disturbing signs that foreign fighters — including some linked to al-Qaida — might be making a new push to sow an Iraq-style insurgency.

Stability also is threatened by a rise in crime, such as gangs kidnapping foreigners in Kabul. Opium and heroin trade is booming and resentment has grown toward the presence of U.S. forces.

Information on the missing SEAL team is from an Army Times report.