United Airlines Flight 831 left Dulles airport in the morning and was bound for Cancun but instead landed safely in Havana after “the crew noticed an unfamiliar smell in the cabin,” spokesman Charles Hobart said in a statement.

“In an abundance of caution, the pilots decided to land the aircraft at the nearest available airport,” he said. “The plane landed routinely and safely in Havana and we are working to re-accommodate our customers.”

Cuban airport and other officials contacted by The Associated Press had no immediate comment.

“We have nothing to inform,” said an operator who answered the phone at the airport.