A passenger jet has crashed in the southern Russian city of Rostov-on-Don killing all 55 passengers and seven crew on board, officials say.The FlyDubai Boeing 737-800, coming from Dubai, missed the runway as it attempted to land at 03:50 local time (00:50 GMT) on Saturday.It is not clear what caused the crash but poor visibility and high winds are being considered as a factor.There were reports of a fire or an explosion on board.Reports say the plane abandoned its initial attempt to land and circled for two hours before crashing at the second attempt.It came down about 250m (800ft) short of the start of the runway in Rostov, some 950km (600 miles) south of Moscow.Most of the passengers on board flight FZ981 were Russian, the regional governor said. Another official said three foreigners were on the passenger list, Reuters reported, but this has not been confirmed.A CCTV video showed what appeared to be a plane landing at the airport before being engulfed in a huge fire.About 700 rescue workers were sent to the site of the crash and the fire was extinguished, media reports said.A search is under way for the plane’s flight recorders and an investigation has been opened into the cause of the crash.Other flights have been diverted away from the airport.In a statement on its Facebook page, the airliner confirmed the ‘tragic accident’ and said an emergency response has been put in place.Boeing said on Twitter its team was working to gather more details.FlyDubai, a low cost carrier launched in 2009 with a hub in Dubai, operates flights to some 90 destinations.