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

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