An Azerbaijani cargo plane crashed in the mountains on its way to a U.S.-NATO air base in Afghanistan late Tuesday, officials said, and all nine crew members on board are believed to have been killed.

No Americans were on the flight, officials said.

The Russian-made IL-76 was en route from Baku to Bagram air base, the hub of U.S. military and NATO forces in Afghanistan. Officials said the plane was flying at about 12,500 feet when it went down in a mountainous part of the Ghorband valley, west of the base and north of Kabul.

Taliban insurgents, who have recently become active in Ghorband, claimed that the plane was shot down. But Basir Salangi, governor of the province that includes Ghorband, said the plane was flying well above the range of Taliban weapons.

Quoting officials sent to the site of the crash, Salangi said the plane was completely destroyed and that all those on board had died.

Maj. Tim James, a spokesman for the NATO coalition in Afghanistan, said there is “absolutely no indication that there was any insurgent activity” in the area at the time of the crash.

But the Associated Press later reported that Afghan police investigating the crash were ambushed by militants. There were no injuries.

The United States and NATO increasingly are relying on air transport to ferry supplies into Afghanistan, as tensions between the United States and Pakistan threaten land routes from that country.

Air travel carries its own risks. Last year, dozens of people — including a group of foreigners — were killed when a fixed-wing Afghan plane crashed in a mountainous area close to the site of Tuesday’s crash. In October, a civilian cargo transport plane crashed into mountains in the outskirts of Kabul, killing all eight foreigners on board.

Maj. James Lowe, a spokesman for the U.S. Transportation Command, said the aircraft that went down Tuesday was carrying about 4,000 pounds of heavy equipment on four pallets.

“The plane belonged to Azerbaijan and was chartered by the coalition and was flying supplies for them to Bagram,” said Yaqoub Rassouli, head of Kabul Airport.

AP reported that four crew members were Azerbaijani, three were from Uzbekistan and two were from Russia.

Salahuddin is a special correspondent.