Four people have died after a small plane crashed near Dubai International Airport on Thursday evening. The two pilots and two passengers were killed when the Diamond DA42 aircraft came down around 7.30pm following a malfunction, officials said. A statement from the General Civil Aviation Authority said three of the dead were British and one was from South Africa. The four-seat, twin-engine propeller aircraft was registered in the UK and crashed around 5 kilometres south of the airport. It is believed the passengers were flying to "calibrate terrestrial navigation systems" at the airport, which is undergoing work. Dubai International Airport, the world's busiest by international traffic, diverted a number of flights between 7.36pm and 8.22pm. It put other planes in a holding pattern over the Gulf while emergency crews responded to the incident. The exact circumstances of the accident are not yet known and it is not clear if the aircraft was taking off or landing when the crash happened. Officials identified the plane as a DA42 model, manufactured by Chinese company Diamond Aircraft Industries, based in Austria. "An accident involving a small plane with four passengers occurred resulting in the death of the pilot and his assistant. The relevant teams are on the scene," Dubai Media Office said. The plane’s tail number belongs to Flight Calibrations Service based in the UK, AP reported. The company refused to comment on reports that it was contracted to do runway work at Dubai International Airport. “We are deeply saddened by today’s plane crash in Dubai, and our heartfelt condolences are with the victims’ families," engineering and aerospace manufacturer Honeywell said. "The plane was not owned or operated by Honeywell but by a third party engaged by Honeywell. We are waiting for more details." State news agency Wam said at 8.52pm on Thursday that all operations at the airport were back up and running. On Friday morning, police and flight investigators continued to work at the crash site. Dubai International is currently operating at a reduced capacity because of ongoing work to one of its runways. Large amounts of traffic are being diverted to Dubai World Central, the city's second airport, close to the Expo 2020 site. Dubai International has one of the safest records of any major airport. The only other major incident in recent years was when Emirates Flight 521, from Thiruvananthapuram in Kerala, crashed on the runway on August 3, 2016. All 300 passengers and crew survived, with 30 taken to hospital mostly with minor injuries or for precautionary check-ups. The fuel tank of the Boeing 777 exploded in an ensuing blaze, killing firefighter Jassim Al Baloushi, 27, from Ras Al Khaimah. The following flights were cancelled or delayed: Multan flight PA810 delayed, from 5.10pm until 10.10pm Bahrain Gf578 cancelled 8.15pm Chongqing Jiangbei CA451 due 9.10pm expected 10.23pm Kathmandu FZ576 due 10.45pm expected 11.53pm Bologna EK094 due 11.30pm expected 12.01am