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POLICE halted Climate Camp marchers in Harmondsworth after they refused to say where they were going.
Hundreds of protesters found themselves in gridlock near the junction of Holloway Lane and High Street, after an hour and a half of steady progress round the perimeter of the proposed third runway.
The deadlock has now been resolved, with officers agreeing protesters can continue to march.
Sources amongst the campaigners also say a group of teenage girls have occupied the roof of a building next to BAA's corporate headquarters, in Mondial Way, off Bath Road, near Heathrow Airport.
More updates will appear throughout the day on this site from our reporters at the scene of the protest.
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