Two Hong Kong airport security staff were killed when a cargo plane skidded off a runway, hit their patrol vehicle, and ploughed into the sea.

Emirates flight EK9788 was arriving from Dubai at about 03:50 local time on Monday (19:50 GMT on Sunday) when it veered off the runway, crashed through perimeter fencing, and collided with the vehicle, pushing it into the water.

The two people inside died. The Boeing 747 ended up partly submerged, but its four crew survived.

Officials are investigating the cause of the crash on the north runway. Two other runways remain operational. It is one of the deadliest aviation incidents in years at Hong Kong International Airport, which has a good safety record.

The investigation will focus on the unanswered questions over the path taken by the plane upon landing.

Airport officials have said they gave the correct instructions to the plane and that there were signs on the runway to guide aircraft.

Airport operations executive director Steven Yiu said the patrol car was, at the time, travelling on a road outside of the runway's fencing at a safe distance from the runway.

The plane then turned away from the runway, crashed through the fencing, and collided with the vehicle, pushing it into the sea, Mr. Yiu explained.

Normally the plane is not supposed to turn towards the sea, he said at a news conference hours after the incident, adding that the plane did not send out a distress signal when it was landing.

Divers managed to locate the bodies of the patrol vehicle's driver and passenger.

The two dead ground staff were aged 30 and 41, and had seven and 12 years' experience, respectively. Neither was breathing when recovered from the vehicle, which was five metres (16.4 feet) from shore and seven metres under water. The younger of the two was confirmed dead at the scene, and the other later in hospital.

An Emirates spokesperson said in a statement to the BBC that the plane sustained damage on landing in Hong Kong, adding: Crew are confirmed to be safe and there was no cargo onboard.

The investigation into this tragic incident continues, as officials seek to understand what went wrong.