Updated

NATO (search) helicopters searching for an Afghan passenger jet that disappeared during a snowstorm found the wreckage of the plane Saturday in the forbidding mountains east of the capital, and officials said all 104 people aboard appeared to have been killed. Six Americans were believed to have been on board, sources told FOX News.

Maj. Karen Tissot Van Patot, an alliance spokeswoman, said two helicopter gunships spotted the tail and other parts of the plane on Saturday afternoon about 20 miles east of Kabul at an altitude of 11,000 feet.

Helicopters dropped Slovenian mountain rescue teams at the scene, Tissot said. Hundreds of Afghan troops were preparing for the grisly job of picking through the wreckage and collecting the bodies, the military said.

"So far we don't think there are any survivors," said Lutfullah Mashal, a spokesperson for the Afghan Ministry of Interior. "The plane is completely destroyed."

The Boeing 737-200, flown by Kam Air (search), post-Taliban Afghanistan's first private airlines, vanished from radar screens on Thursday afternoon as it approached Kabul airport in poor weather, sparking a massive search operation for the 96 passengers and eight crew, at least 21 of them foreigners. Six Americans were believed to have been on board, the U.S. Embassy in Kabul said, which is double the number previously reported. Three of the Americans were said to be working for a nonprofit group.

There was no indication that the plane, which was arriving from the western Afghan city of Herat, was hijacked or brought down by a bomb, Defense Ministry spokesman Gen. Mohammed Zahir Azimi said.

If all are confirmed dead, it would be this war-wracked nation's deadliest air disaster.

Hundreds of Afghan and NATO forces began the search early Friday. They were using Chenari, a village at the foot of tall mountains between Kabul and the eastern city of Jalalabad, as a base. Rescue workers on Saturday were hampered by thick snow and freezing fog that enveloped the tall mountains which ring the capital. Helicopters were held on the grounds for hours early Saturday by poor visibility.

Kam Air made its maiden flight on the Kabul-Herat route in November 2003. Its mainly domestic flights using leased Boeing and Antonov planes are popular with wealthy Afghans and also are used by aid and reconstruction workers.

However, there have been concerns about the safety of its planes as well as those of state-owned Ariana Airlines.

U.N. staff are banned from using either. However, spokeswoman Ariane Quentier confirmed on Saturday that an Italian man working as an architect for the U.N. Office for Project Services was on board. Italian authorities said another Italian civilian and a navy captain were among the 96 passengers.

Turkey's prime ministry said Friday that nine Turks were aboard the missing plane.

Kam Air said the eight-member crew comprised six Russians and two Afghans.

The last major plane crash in Afghanistan was on Nov. 27 last year, when a transport plane under contract to the U.S. military crashed in central Bamiyan province, killing three American soldiers and three American civilian crew.

The most recent commercial crash was on March 19, 1998, when an Ariana Airlines Boeing 727 slammed into a peak near Kabul, killing all 45 passengers and crew.

The Associated Press contributed to this report.