“The remaining seven people are believed to be inside the aircraft but are currently inaccessible due to the condition of the plane,” the Coast Guard said on X.

The wreckage in snowy terrain was discovered 55km southeast of Nome, the coast guard said in a post that included a picture of the wreckage in the snow and two members of the recovery team.

“Our heartfelt condolences are with those affected by this tragic incident,” the coast guard said.

The Cessna 208B Grand Caravan aircraft carrying a pilot and nine adult passengers was reported missing en route from Unalakleet about 4pm local time on Thursday, according to a dispatch posted on the website of the Alaska state troopers in Nome, which is more than 805km northwest of Anchorage.

The plane went missing about 19km offshore over the icy waters of the Norton Sound, which is part of the Bering Sea, according to the coast guard.

Benjamin McIntyre-Coble, an officer with the coast guard in Alaska, has said the plane suffered a rapid loss of altitude and speed, according to radar data, but could offer no details on what may have caused that. Weather was wintry and poor in the area where the plane suddenly dropped, officials said.

The plane was operated by Bering Air and was making a 240km trip from Unalakleet to Nome, a regularly scheduled commuter flight that traverses the Norton Sound. Family of those on board have been notified, but no names have been released.

Clint Johnson, chief of the National Transportation Safety Board (NTSB)’s Alaska office, said during a Friday press conference that the NTSB has begun its investigation, but that search and rescue operations were the focus.

The incident comes at a time of heightened scrutiny of air safety in the US. NTSB investigators are probing two deadly crashes in recent days: the midair collision of a passenger jet and US Army Black Hawk helicopter in Washington, which killed 67 people, and a medical jet crash in Philadelphia that killed seven.