An amateur video has emerged on YouTube, showing police venting steam on alleged rioters in Manchester. A group of young people were biking along a street when officers ran them down, slamming one suspect to the ground and beating him with batons. The video is said to have been taken two days ago, at the peak of the violence in the country. Police have promised an investigation. Officers have been authorised to use water cannons and non-lethal bullets to disperse further riots.