An Air Canada Express regional jet collided with a Port Authority vehicle after landing at New York's LaGuardia Airport late Sunday night, injuring four people and forcing closure of the airport.

The New York City Fire Department responded to reports of the collision at 11:38 p.m. Sunday. The Federal Aviation Administration issued a ground stop for all flights at LaGuardia, with the airport remaining closed early Monday morning.

Four people were injured in the incident, according to sources familiar with the matter. Multiple sources identified the ground vehicle as either a fire truck or Port Authority vehicle, though exact details varied among reports.

Social media videos posted by bystanders showed the Air Canada aircraft with severe damage to the front of the plane, with one witness describing the nose as "sheared off." The collision occurred on a runway at the airport.

The New York Police Department confirmed the collision occurred but could not immediately provide additional details. Port Authority and federal aviation officials have not yet released official statements about the cause of the incident.

The airport closure prompted warnings from New York's emergency management authority for travelers to expect flight cancellations and delays. LaGuardia is one of the busiest airports serving the New York metropolitan area.