Activists who are trying to form a separate English-speaking country from part of the West African nation of Cameroon are starting a court action following the killings of three demonstrators this week.

The English-speaking separatists are going to court to try to win the release of scores of demonstrators who were arrested during violent protests in recent days.

The protests have centered on the Anglophones' drive to declare an independent state called Southern Cameroon in the north and southwest of the country.

Cameroon was formed in 1961 when French Cameroon and British Cameroon merged into a federation. Following a referendum in 1972, that federation became the United Republic of Cameroon. The country was renamed the Republic of Cameroon by current President Paul Biya in 1984, two years after he took office.

English-speaking Cameroonians have long complained that French-speakers have kept them out of top posts in the government. Anglophones also complain that many government documents are printed only in French, even though English is also the official language.

Tensions erupted on Monday, when Anglophone pro-independence demonstrators took to the streets in the northwestern cities of Bamenda and Kumbo, after authorities imposed a ban on protests.

News reports from the scene say security forces opened fire at the demonstrators in Kumbo, killing three protesters. There was a similar crackdown in Bamenda, where police arrested two opposition leaders, Nfor Ngala Nfor and Martin Luma, of the Southern Cameroon National Council opposition group.

A curfew remains in place in the English-speaking parts of the country, and hundreds of troops have been deployed.