A number of Britons were among 19 tourists killed as a hot air balloon exploded and crashed near the Egyptian city of Luxor.

Witnesses described hearing a loud explosion before seeing plumes of smoke as the balloon caught fire and plunged into a sugar cane field west of Luxor, which is 320 miles south of the capital Cairo.

The casualties are believed to include British and French tourists, as well as other nationalities, a security official in the country said.

A spokesman for air balloon tour operator Sky Cruise said there were two survivors, including the pilot, who is in a serious condition in hospital. He said it was believed there were "about four" Britons on board.

Witness Christopher Michel described the carnage on Twitter, where he posted a series of photographs showing the balloons ahead of the flight. He said: "It was the balloon behind mine. I heard a loud explosion and saw smoke."

According to one report, the accident happened after a gas explosion at an altitude of 1,000ft.

Mr Michel, who previously made a balloon excursion with an English pilot, said the Egyptian operation "didn't feel quite as professional" as that of his first voyage. The US photographer was taking aerial photographs at the time of the crash.

A Foreign Office spokesman said: "We are aware of the reports and we are making urgent inquiries with the authorities in Egypt."

UK travel organisation Abta was seeking more information about the accident, as were the UK holiday companies who have people in Luxor at the moment. Thomas Cook said: "We are getting in contact with our people in Luxor to get the very latest news. Luxor is a popular spot for us and a number of tourists go on balloon trips."

A spokesman for UK travel organisation Abta said: "We are aware that there have been a number of injuries and fatalities including British nationals following an incident involving a hot air balloon trip in Luxor, Egypt, operated by a local company, Skycruise. It is understood that at least 20 people were on board the flight, although it has not yet been confirmed how many of these are British nationals. We are working with our members, the Foreign Office and the Egyptian authorities to ascertain more details about the incident."