A Southwest Airlines plane has made an emergency landing at Philadelphia’s airport with part of the covering from its left engine ripped off and a window damaged.

It was not immediately known if anyone on board was injured, and neither the airline nor the Federal Aviation Administration explained what went wrong.

Southwest said there were 143 passengers and five crew members on board the Boeing 737, which was heading from New York’s LaGuardia Airport to Dallas’ Love Field.

Passengers were seen walking off the plane onto the tarmac at the airport after landing at around 11:20am local time.

The Philadelphia airport tweeted that Flight 1380 “landed safely at PHL and passengers are being brought into the terminal”.

The Federal Aviation Administration said that the plane landed after the crew reported damage to one of the plane’s engines, along with the fuselage and at least one window.

Passenger Marty Martinez did a brief Facebook Live posting while wearing an oxygen mask. He posted, “Something is wrong with our plane! It appears we are going down! Emergency landing!! Southwest flight from NYC to Dallas!!”

After the plane landed, he posted photos of a damaged window near the engine.

News helicopter footage showed damage to the left engine and the tarmac covered with firefighting foam, although there were no signs of flames or smoke.

Tracking data from FlightAware.com shows the flight was heading west over New York’s southern tier when it abruptly turned toward Philadelphia.

Southwest has about 700 planes, all of them 737s, including more than 500 737-700s like the one involved in Tuesday’s emergency landing.