CHEEKTOWAGA, N.Y. (AP) — Crews are trying to determine the source of an unusual odor that prompted an American Airlines flight to make an emergency landing in Buffalo.

Airport officials say a number of people aboard Flight 9879 from Philadelphia smelled smoke about 3 p.m. Monday.

The Buffalo-bound flight with 37 people on board made an emergency landing, but crews did not find any evidence of fire.

The Niagara Frontier Transportation Agency says no one was hurt and the cause of the odor is under investigation.