Man sprints onto Heathrow runway in security breach

A man sprinted onto a runway at London's Heathrow airport on Thursday, the day before Queen Elizabeth was due to open its giant new Terminal Five, in the second major security breach in less than a month.

An aircraft prepares to land at Heathrow airport in London March 11, 2008. A man was arrested on Thursday after running onto a runway at London's Heathrow airport carrying a bag, police said. (REUTERS/Alessia Pierdomenico)

Police arrested the man and blew up his bag in a controlled detonation but found no bomb, a spokeswoman said.

The world's busiest international airport has been the target of protests from environmentalists angered at the opening of the new terminal and plans to boost traffic with the addition of a third runway and a sixth terminal.

"I can confirm that at approximately 2:05 p.m. (1405 GMT) a man was seen airside at Heathrow airport on the northern runway. He's been arrested by police and he's currently in custody," a police spokesman said.

Last month protesters opposing the expansion plans breached the airport's security to unveil a banner on top of a parked passenger jet. Others chained themselves to the roof of parliament. Organisers have threatened more action.

Police declined to speculate on the arrested man's motives.

Television pictures showed several emergency cars with flashing lights parked on the airport runway.

About two hours after the incident airport operator BAA said both runways had reopened.

"Some short delays have occurred but we are expecting to return to normal later this afternoon," said a spokeswoman for BAA, owned by Spanish firm Ferrovial.

A spokesman for Queen Elizabeth said there were no plans to cancel her appearance at Friday's opening ceremony for the new Terminal Five.

"At this stage there's no reason to expect that it will not go ahead as planned," a spokesman for the Queen said.

Security at the airport has also been a high-profile issue since 2006 when British authorities said they had thwarted a plot to smuggle explosives onto trans-Atlantic flights.

"The important thing about the Heathrow incident is that the person was detained, that all the security precautions went quickly into action, that he's now being interviewed and that all possible steps were taken," Prime Minister Gordon Brown told reporters at a European summit in Brussels.