Danish police released Sunday hundreds of activists who were detained during a mass rally demanding strong action from delegates at the UN climate conference. Police said only 13 of the 968 people detained during and after the demonstration in Copenhagen remained in custody Sunday. Of those, three – two Danes and a Frenchman – were set to be arraigned in court on preliminary charges of fighting with police. The conference took a day off Sunday, though environment ministers were meeting for informal talks on greenhouse emissions cuts and financing for poor nations to deal with climate change. The pledges on emissions cuts so far are short of the minimum proposed in a draft agreement to keep temperatures from rising to a dangerous level. About 40,000 people joined Saturday's mostly peaceful march toward the suburban conference center where the 192-nation UN climate conference is being held. Riot police detained activists when some of them started vandalizing buildings in downtown Copenhagen. Windows were broken at the former stock exchange and the Foreign Ministry. A police officer received minor injuries when he was hit by a rock thrown from the group and one protester was injured by fireworks, a police spokesman said. The majority of peaceful demonstrators chanted and carried banners reading “Demand Climate Justice,” “The World Wants a Real Deal” and “There is No Planet B,” navigating for miles along city streets and over bridges past officers in riot gear, police dogs and the flashing lights of dozens of police vans.