A charter plane crashed at a remote radar site in Alaska on Thursday, killing all eight people on board, the U.S. military said.

The crash happened at Cape Newenham Long Range Radar Site Airport, some 450 miles west of Anchorage.

“This is a devastating loss for our military family and the communities we serve,” U.S. Air Force Lt. Gen. Robert Davis, commander of Alaskan Command, the Alaskan North American Aerospace Defense Command Region and Eleventh Air Force, said in a statement.

“These individuals were dedicated professionals carrying out a vital mission in a demanding environment. Our absolute priority right now is providing unwavering support to their families, friends, and teammates during this devastating time. We are profoundly grateful for the swift and tireless response of our search and recovery professionals.”

It was not immediately clear what mission the group was carrying out. The statement said the plane was a “civilian-contracted aircraft.”

Cape Newenham Long Range Radar Site is part of a network of remote radar sites that track aircraft operating in Alaska’s airspace and along its borders. It is managed by the Pacific Air Forces Regional Support Center, the statement from Alaskan Command said.

Two pilots and six passengers had been on board, according to Clint Johnson, the National Transportation Safety Board’s Alaska region chief. He said earlier that the plane was believed to have crashed Thursday afternoon while approaching Cape Newenham after taking off from Anchorage.

The military statement said that following the crash, search and rescue teams landed near the site and ultimately confirmed there were no survivors.

The names of those on board will be released 24 hours after their next of kin are notified, the military said.