Tensions boiled over on the freezing streets of Copenhagen as police officers fired tear gas and wielded batons to beat back protestors at the climate summit.
Authorities tried to disperse the crowds as they made their way to the Bella centre, the venue where 194 countries are trying to thrash out a deal to stave off global warming.
Police say around 260 demonstrators have been arrested.
The movements for global justice intended to take over the conference for a day and form a people’s assembly.
However, police moved to block off the Bella Centre.
Prior to the COP 15, the Danish justice ministry introduced a wide range of emergency laws to help police combat civil disobedience.
Action groups describe the moves as draconian and heavy handed.
Meanwhile, inside the centre delegates tried to disrupt proceedings by leaving the building to join up with demonstrators outside, but they too were driven back by security officials.
The UN climate change chief Yvo de Boer tried to calm things down.
But the voice of protest continued to be heard.