A group of anti-government demonstrators have clashed with police in central Athens at a rally to shut down high-security prisons. Protesters hurled petrol bombs and set cars ablaze, while riot police responded with tear gas and detained four people. COURTESY: RT's RUPTLY video agency, NO RE-UPLOAD, NO REUSE - FOR LICENSING, PLEASE, CONTACT http://ruptly.tv RT LIVE http://rt.com/on-air Subscribe to RT! http://www.youtube.com/subscription_center?add_user=RussiaToday Like us on Facebook http://www.facebook.com/RTnews Follow us on Twitter http://twitter.com/RT_com Follow us on Instagram http://instagram.com/rt Follow us on Google+ http://plus.google.com/+RT Listen to us on Soundcloud: https://soundcloud.com/rttv RT (Russia Today) is a global news network broadcasting from Moscow and Washington studios. RT is the first news channel to break the 1 billion YouTube views benchmark.