All four people aboard a small plane that crashed shortly after taking off from London Southend Airport are dead, police said Monday.

Essex Police said that work is continuing to formally identify the victims, none of whom are British.

The Beechcraft B200 Super King Air operated by Dutch firm Zeusch Aviation had flown from Athens, Greece to Pula in Croatia on Sunday before heading to Southend. It was due to return to its home base of Lelystad, in the Netherlands, on Sunday evening. The 23-meter (39-foot) turboprop plane came down moments after takeoff and burst into flames.

“Sadly, we can now confirm that all four people on board died,” Essex Police chief superintendent Morgan Cronin told reporters. “We are working to officially confirm their identities. At this stage, we believe all four are foreign nationals.”

Zeusch Aviation operates medical evacuation and transplant flights as well as aerial mapping and private charters, according to its website.

London Southend is a relatively small airport, around 45 miles (72 kilometers) east of the British capital, used for short-haul flights by airlines including easyJet. The airport remained closed on Monday with no word on when it would reopen.

Britain’s Air Accidents Investigation Branch said it has sent a “multi-disciplinary team including inspectors with expertise in aircraft operations, human factors, engineering and recorded data” to the airport.

The Beechcraft B200 Super King Air, first built in the 1970s, is an aviation workhorse used for a wide variety of roles around the world. In 2017, a plane of the same model crashed into the roof of a shopping mall in Melbourne, Australia moments after takeoff, killing the pilot and four American tourists.