Five police have been killed in fresh violence in western Cameroon, where English-speaking separatists have declared an independent state, security sources and witnesses said on Monday.Four gendarmes were killed in Esu, a village near the town of Wum in Northwest Region, when their unit came under attack on Sunday, a source close to the regional security services said."The attack happened in the morning - they were new recruits who were caught off-guard," the source said, adding that there also were wounded.The inhabitants of Esu fled after the attack, one of them said."Many people were so afraid that they went off into the bush - others are trying to get to Bamenda," the capital of Northwest Region, the source said.In neighbouring Southwest Region, a police officer named Ekah Njume was killed on Sunday at his home in Mutengene, near the capital Buea, by unidentified assailants, witnesses and local press reports said on Monday.The two regions are predominantly home to English-speakers, a minority comprising about a fifth of the 22 million people in Cameroon, a largely French-speaking West African state.Years of resentment among anglophones at perceived discrimination fuelled demands in 2016 for a return to the country's federal structure.President Paul Biya, 85, took a hard line, ruling out any concessions.As the situation polarised, anglophone militants last October 1 made a symbolic declaration of independence that met with a government crackdown.Since then, the two regions have been hit by almost daily acts of violence and retribution.Scores of police and troops have been killed, as well as more than 100 civilians, according to a government report in July.According to UN data, the violence has caused more than 21 000 people to flee to neighbouring countries, while 160 000 have been internally displaced, with many reportedly hiding in forests.Cameroon's large English-speaking minority is a legacy of the colonial period.The former German colony was divided between Britain and France after World War I.In 1960, the French colony gained independence, becoming Cameroon. The following year, the British-ruled Southern Cameroons were amalgamated into it, giving rise to the Northwest and Southwest regions.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.