A traveller onboard an Air Canada flight from Edmonton to Toronto says he was surprised to see police officers remove a passenger from the plane after it was diverted to Thunder Bay, Ont., last Friday.

Alan Bell told CBC News that on Jan. 12, his flight made an unscheduled stop in the northwestern Ontario city.  The captain had told passengers the plane was landing in Thunder Bay because of inclement weather in Toronto, but when they landed, city police officers entered the plane.

"Shortly after landing, they opened the door [and] three cops came on board and extracted a guy from the plane," Bell said.

According to a media release from the Thunder Bay Police Service, officers were dispatched to the airport, where they boarded the plane, just after 4 p.m.

Bell said he was completely unaware anything was wrong as "everything seemed normal," and there was no "fuss or muss."

Police said they were alerted about the man by the flight crew. Officers requested that the man exit the plane.

A 31-year-old from Ottawa was arrested outside the plane and subsequently charged with assault in an aircraft in flight and is scheduled to appear in court on Tuesday.

An Air Canada spokesperson said the plane was on the ground in Thunder Bay for about an hour before continuing to its destination.