File photo: The airline said that a maintenance team was examining the aircraft following the incident. Picture: AP

We've heard of turbulence and medical emergencies diverting flights. But a nasty smell? That's something new. Well, that's exactly what happened when an American Airlines flight was diverted because of an unknown smell.

According to News Week, the plane was flying to the UK from Philadelphia. And less than two hours into the flight, the Airbus A330-300 ended up making an emergency landing at Boston's Logan Airport.

"I kept smelling a funny smell, and I wasn't quite sure what it was. I thought someone had an upset stomach, so I ignored it," one passenger told WBZ-TV.

Another said: "It smelled kind of more like a sort of burning smell I would have thought. But more like a strange burning smell."

The airline said that a maintenance team was examining the aircraft following the incident. However, 10 crew members were taken to hospital for further evaluation. 

In a statement, the airline said: "Flight 728 from Philadelphia to London Heathrow was diverted to Boston after a possible odor was reported in the cabin. 

"No passengers experienced any issues, but their trip has been put on hold temporarily. All passengers were provided overnight accommodations in Boston."