Armed police arrested three men on a plane at London Heathrow at the weekend amid fears of a terror threat. They swarmed the Dubai-bound Emirates plane as it taxiing on the tarmac before take-over.

Terrified passengers watched as police with automatic weapons stormed on to the flight.

Witnesses said counter-terrorism handcuffed the suspect, described as a white male, and bundled him off the aircraft. Another individual was also arrested, according to police sources.

Airports are on high alert following the failed Christmas Day bombing on a plane as it landed in Detroit in the US.

The raid came af ter a “verbal threat” as the plane taxied to the runway. Its pilot immediately returned the plane to the terminal.

Three men were arrested and taken of f the plan. Passengers were kept aboard the jet for more than four hours as sniffer dogs searched the cabin.

It later emerged the threat was likely to have been made by a drunk English passenger.

Traveller Cameron McLean said: “The police just swarmed the guy and rushed him out.

“The man seemed pretty calm and there was no shouting or screaming. He gave in straight away.”

The airport remained open during the drama.

An airport spokesman said: “I can confirm there has been an incident on the EK004 flight to Dubai. Police are attending. It’s not affecting the rest of the airport which remains opens.”

Passengers at Heathrow airport will be the first to undergo checks by full-body scanners.

The move came after Gordon Brown committed Britain to using the controversial technology, saying airports had to ‘go further’ on security measures following the failed Christmas day terror attack on a transatlantic passenger jet.

Meanwhile, the Nigerian charged with the Detroit bombing attempt appeared in court last night AA grand jury indicted Umar Farouk Abdulmutallab, 23, on six charges, including the attempted use of a weapon of mass destruction aboard Northwest Airlines Flight 253.

The offence carries a sentence of up to life in prison.