The FAA tells Eyewitness News that an Air Transat Flight 942, a Boeing 737, reported a possible fire in the cargo hold and diverted to Newark around 8:30 a.m.
The aircraft landed and remained on the runway while firefighters responded. Passengers evacuated on the runway via emergency slides, the FAA said.
The flight reportedly departed from Montreal, Canada, and was heading to Fort Lauderdale, Florida.
Newark Airport tweeted that all runways were closed due to an "airport emergency," but flights have resumed since.