A US military aircraft with four crew on board is thought to have crashed in Norway while taking part in NATO exercises, Norwegian emergency services said on Friday.

The US Osprey aircraft “was reported missing at 18:26 (1726 GMT) south of Bodo” in northern Norway in bad weather, the regional emergency services (HRS) said in a statement, Inquire.Net reported.

The four-person crew were taking part in the Cold Response military exercises involving 30,000 people from NATO and partner countries.

The US Marine Corps confirmed “a mishap” involving a MV-22B Osprey during the exercises and said in a statement that Norwegian civil authorities were leading the search and rescue efforts.

Rescuers searching from the air saw signs of the aircraft in the area where it went missing but the weather was too bad for them to land, the Norwegian emergency services said.

Rescue teams and police were heading to the area, it added.

“We are not at the site itself so we know nothing of the four people who were on board. But we know it is a crash site,” HRS spokesman Jan Eskil Severinsen said on the NRK television channel.