Four people have been named suspects and face more than five years in jail over a violent clash between protesters and police in Indonesia's sensitive Papua Province, police said on Thursday.

"The four protesters could be charged with assault against persons or property under Indonesian criminal law," Bagus Eko Danto, the provincial police chief, said. He added that the charges carried maximum sentences of five-and-a-half years.

Police opened fire when angry workers attacked them with homemade guns, machetes and wooden stakes during a protest in the mining town of Timika last month, wounding at least four people.

The workers, who had come from the nearby Kei Islands, were demanding justice for a man who was allegedly shot by police in a local bar a few days earlier and subsequently died.Despite charging the protesters, Danto said no legal action would be taken against police for firing into the crowd.

"Our officers had no choice but to open fire because the protesters were very violently trying to break into our police post. "The police didn't break the law because they were defending themselves," Danto said.