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Climate Camp protesters are continuing to march despite being stopped a number of times by police.
At around 1pm this afternoon (Sunday), officers surrounded a group of about 30 activists who had broken away from the main march because the activists refused to say where they were going. The remaining marchers were also halted by police.
After a brief scuffle between officers and protesters, the march got back underway, and is now heading towards BAA's corporate headquarters which are in Mondial Way, off Bath Road, near Heathrow Airport.
Christine Shilling, a spokesman for No Third Runway Action Group, said: "I'm delighted to see so many people taking part in the protest but I'm concerned, and somewhat alarmed, at the heavy police presence.
"There's a cordon of police officers. It's a bit excessive."
More updates will appear throughout the day on this site from our reporters at the scene of the protest.
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