A young protester in Guinea was killed Tuesday in clashes with police who broke up an anti-government march and prevented the opposition leader from leaving his home."My brother was killed by a policeman who shot him in cold blood," Mariama Dalanda, in tears, told AFP.The death of the 30-year-old man was confirmed by the head of the opposition and former prime minister Cellou Dalein Diallo, adding that 15 other protesters were injured."As of today 98 members of the opposition have been killed by police gunfire at peaceful demonstrations since (President) Alpha Conde came to power in December 2010," Diallo said.Police had surrounded his home, blocking him from joining the protest march in the capital Conakry. At least five of Diallo's supporters were injured earlier Tuesday in confrontations with police near his home, an AFP correspondent at the scene reported. "We are here to prevent Mr Dalein Diallo from leaving his home and going to an unauthorised march," a police official who requested anonymity told AFP.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and FacebookLater a national police chief, Colonel Ansoumane Camara, said the authorities were seeking to protect Diallo."He is at his home... protected and secure," Camara said, adding that police wanted to avoid last week's scenario."Cellou said someone tried to take his life. We are ensuring his security this time," he said.Rivals of Conde had called for Tuesday's march a week after a banned demonstration during which Diallo alleged that police had tried to assassinate him - a claim police have denied. An inquiry has been opened into the incident."It's sad for my country," Diallo, standing outside his home Tuesday, told journalists, calling the police action a violation of freedom and the constitution by Conde.The political opposition has been protesting against what it considers a violation by the authorities of an agreement reached in August over the appointment of local government officials, elected in a hotly disputed vote on February 4.On Monday a "dead city" strike gripped Conakry over another issue that has plagued the West African country; the failure to resolve a pay dispute with teachers who began an unlimited walkout on October 3.