All three London airports - Heathrow, Gatwick and Stansted - were put on standby after news broke that the Sudan Airways Airbus 310 had been hijacked minutes after leaving Khartoum in Sudan on a flight to the Jordanian capital, Amman.
The hijackers forced the captain to fly the plane to Larnaca airport, in Cyprus, where police said the gang told them they had TNT and grenades on board, and would blow up the plane if it was not refuelled and flown to London. The gang is thought to be seeking political asylum in this country.
The Cypriot authorities confirmed the plane landed at Larnaca at around 11.15pm local time (8.15pm UK time). They agreed to the hijackers' demand to refuel the plane and the aircraft took off again, en route for London, just before midnight, UK time.
Although the hijackers asked for the plane to land at Heathrow airport, police in Britain said Stansted airport, in Essex, was the most likely destination, if the plane is allowed to land here at all.
A huge security operation was launched at Stansted last night in preparation for the arrival of Sudan Airways flight 150. Police said they had tactical firearms units standing by and access to hundreds of extra officers and specialist anti-terrorist squads if necessary. A spokesman said the drill for such an incident had been rehearsed many times.
It emerged that the gang originally wanted to fly to Rome but changed their minds and forced the pilot to set a course for Cyprus.
Glafcos Xenos, a police spokes-man in Cyprus, said the hijackers told air traffic controllers they were armed with grenades and TNT, and that they would blow up the plane if their demands were not met.
Mr Xenos said a request from the Cypriot authorities to allow women and children to leave the plane while it was on the tarmac at Larnaca was refused. However, the hijackers promised they would release all passengers and crew when the aircraft was on the ground in the UK.
The director of the civial aviation authority in Cyprus, Michael Herodotou, said the plane was initially refused permission to land at Larnaca but that it was granted when air traffic controllers learned it was running low on fuel.
Communication channels between the hijackers and the authorities on the ground were kept open by messages relayed through the captain of the aircraft.
As the plane made the four-and-a-half hour flight to the UK during the night, it was not clear how many hijackers were on board, but air traffic controllers in Cyprus said they had heard the pilot making references to more than one hijacker. The nationality of the hijackers was also unclear.
This is the second hijacking this year involving a Sudanese airliner. On 24 March, a Sudan Airways Airbus A320 plane carrying 40 passengers and crew on an internal flight was hijacked and forced to land in Eritrea. The two Sudanese hijackers who seized that plane were seeking political asylum in Eritrea. They surrendered to Eritrean authorities immediately after reaching Asmara, the Eritrean capital.
The Muslim fundamentalist government in Sudan has been fighting a 13- year civil war with rebels who want autonomy. The rebels are mostly Christians in the country's southern region. More than 1.3 million people have died in the conflict and the famines it has brought.
Just before midnight, Cypriot authorities granted the hijackers' request to refuel the plane. Ground crews at Larnaca began to refuel the airliner as it sat on the tarmac, surrounded by police. It then took off for London but it was not clear whether permission to land in the UK would be granted.
Police confirmed that none of the 186 hostages or 13 crew members on board had been released by the armed gang.Reuse content