Dubai, May 17 -- A small plane involved in upgrading a runway at Dubai International Airport crashed Thursday night, killing four people and halting traffic at the world's busiest airport for international travel for nearly an hour.

Authorities gave no explanation for what caused the crash of the Diamond DA62 aircraft with a tail number belonging to Flight Calibrations Service Ltd. of Shoreham, England.

The UAE's General Civil Aviation Authority said the three British citizens and one South African on the plane were killed.

Early Friday morning, police, paramedics and flight investigators worked at the crash site, some 8 kilometers (5 miles) southeast of the airport in Mushrif Park near the city-state's water reservoirs. Police told As...