YAOUNDE (Reuters) - Police in Cameroon shot dead four anti-government demonstrators in one of the Central African nation’s minority anglophone regions on Thursday, police sources said, after a month of sometimes violent protests in the area.

The protesters were marching on a meeting of the ruling Cameroon People’s Democratic Movement (RDPC) in Bamenda, a city in the northwest that is a traditional opposition stronghold when they were confronted by police.

Officers initially tried to scatter the demonstrators using tear gas. A Reuters reporter then saw the police open fire on the crowd, which had continued to grow in size.

Protests first broke out in early November in Bamenda when lawyers and teachers demanded better working conditions in a rare act of defiance against President Paul Biya, 83, who has ruled Cameroon since 1982.

Some demonstrators were armed with steel bars and stones, said one police official, adding that officers had acted in self-defense. One police officer was wounded in the unrest, he said.

“Some of our elements were surrounded by thugs,” the officer said, speaking on condition of anonymity because he was not authorized to talk to reporters. “They had come to kill. The police defended themselves.”

“Four hostile targets were neutralized. It’s possible there were more,” the police source said.

A second officer confirmed four deaths.

A local journalist at the scene, Brenda Kiven, said the ruling party meeting was seen by the protesters as a provocation.