Hong Kong police arrested 12 protesters blocking several roads in the Mong Kok neighborhood overnight Wednesday as pro-democracy demonstrators returned to the site hundreds had occupied for more than two months, police said.

A police statement Thursday said that police used pepper spray and batons to break up the protest and arrested demonstrators on charges ranging from assaulting a police officer to failing to produce proof of identity. The statement said two police officers were injured in the operation.

"Police had made repeated public announcements and displayed warning banners at the scene to urge them to leave the scene but they refused to comply," it said.

Over the last several months, thousands of protesters occupied three busy neighborhoods, including Mong Kok, to demand that residents of the semi-autonomous city be allowed to elect their top executive in 2017 from an open list of candidates. Chinese officials are requiring that a committee believed friendly to Beijing select the candidates.

Police cleared out the last the of the protest sites on Dec. 15.