Newark Liberty International Airport was temporarily closed after the engine of a United Airlines plane caught fire and had to be evacuated.

The airport tweeted Tuesday night that the flight had an apparent engine fire and that passengers were forced to evacuate.

Jonathan Guerin, a spokesman for United, said the tower notified the crew of what appeared to be flames from one of the engines. He said the crew immediately deployed the plane's emergency slides and evacuated the passengers.

Passengers on board United Flight 1579 en route to San Francisco posted on social media that flight attendants yelled for them to get off the plane, and then everyone evacuated out of the side of the plane.

Other passengers posted online that there was a large presence of emergency vehicles, but they did not see any smoke or fire in the plane.

Airport officials later tweeted that five people suffered minor injuries.

The plane headed to San Francisco eventually took off around 1:30 a.m. and arrived around 6:30 a.m. EST, officials said. The cause of the fire remains unclear.

Newark Liberty International Airport reopened around 11 p.m. Tuesday after being closed for about an hour.