Two people have been killed as a cargo plane skidded off a runway while landing at Hong Kong International Airport.

The accident early on Monday saw the plane hit a patrol car which it then swept into the sea, leaving two airport security workers dead, authorities have said.

Steven Yiu, executive director of airport operations at Airport Authority Hong Kong, said the accident happened when the Boeing 747 cargo plane from Dubai landed at the busy hub shortly before 4:00am Monday (20:00 GMT Sunday).

On landing, the plane had gone off the airport’s north runway, crashed through a fence and struck the security patrol car, leaving both vehicles in the sea water that borders the airport, he said. The patrol car had been on the other side of the fence when the aircraft struck it.

A 30-year-old man in the patrol car was confirmed dead at the scene. A man aged 41 died after being rushed to hospital, authorities said.

Both were retrieved from the sunken car by divers about five metres (16 feet) from the shore.

Footage from the scene showed the half-submerged aircraft with its tail section broken off, damage below the cockpit, and the emergency slide activated.

The accident at the world’s busiest cargo airport involved a plane leased from and operated by Turkish freight carrier ACT Airlines on behalf of Emirates, the latter said in a statement.

Emirates said the four crew members on board the plane had been sent to local hospitals for medical treatment.

Yiu said an investigation will aim to determine what caused the aircraft to leave the tarmac, in one of the most serious safety incidents since the airport opened in 1998.

Officials said the weather and runway conditions had been safe for landing at the time of the incident, and the aircraft did not send an emergency signal.

Hong Kong police said they would not rule out launching a criminal investigation.