An Alaska Airlines flight made an emergency landing in Oregon on Friday after a window and chunk of its fuselage blew out in mid-air, media reports said.

A passenger sent KATU-TV a photo showing a gaping hole in the side of the airplane next to passenger seats. It was not immediately clear if anyone was injured.

The airline said it was investigating what happened.

“Alaska Airlines Flight 1282 from Portland, Oregon, to Ontario, California, experienced an incident this evening soon after departure,” the company said in an emailed statement. “The aircraft landed safely back at Portland International Airport with 174 guests and 6 crew members.”

The company said it would share more information when it became available.

The flight left Portland at 4:52 p.m. but returned just before 5:30 p.m.

The plane rose as high as 16,000 feet (4,876 metres) during the flight and then began descending, according to data on the flight tracking website FlightAware.

KPTV-TV reported photos sent in by a passenger showed a large section of the airplane's fuselage was missing.

The FAA did not immediately respond to an email request for information.

The Boeing 737-9 MAX rolled off the assembly line and received its certification just two months ago, according to online FAA records.

The National Transportation Safety Board said in a post on X, formerly known as Twitter, that it was investigating an event on the flight and would post updates when they are available.