Three people face charges after a confrontation between protesters and police outside a Progressive Conservative fundraiser Thursday night in Halifax.

Police said officers suspected several people dressed as Robin Hood were trying to disrupt the event at the World Trade and Convention Centre. When they escorted them out, they were met by about 30 people outside.

The scene turned violent, police said, and one officer was punched in the head.

About 20 other officers responded to a call for help over the police radio. They used pepper spray to disperse the crowd.

The injuries to officers included cuts and broken fingers, police said.

A spokeswoman for the Halifax Coalition Against Poverty said police overreacted and "aggressively" attacked the protesters, who were trying to highlight the widening gap between the province's rich and poor.

Three people were arrested and face charges of assaulting police, resisting arrest and causing a disturbance in a public place. They are expected to appear in court at a later date.