Protesters clashed with Guinean police on Friday at a march by thousands of opposition supporters in the coastal capital Conakry, the latest in more than a week of violence stemming from a dispute over legislative elections.
Activists, who accuse President Alpha Conde of planning to rig the vote planned for May 12, were marking the funerals of nine people killed during rallies over the past 10 days.
Witnesses said a group attacked a temporary police post at a crossroads in the Bambeto neighborhood, near Conakry's international airport, and police responded by firing warning shots and teargas to try to break up the crowd.
"They attacked the (police) post and wrecked it. We fired warning shots but the crowd continued to threaten us," a police official, who asked not to be identified, told Reuters.
Eight police officers were injured and around 10 protesters arrested, he said.
"The crowd has dispersed ... We can still hear the shooting," local resident Souleymane Bah told Reuters by phone. Police reinforcements were arriving on the scene, he added.
Hundreds have been injured since the opposition started rallying in the capital on February 27 and disturbances have also spread to several towns in the interior of the mineral-rich West African country.
Guinea is the world's top supplier of the aluminum ore bauxite and holds rich deposits of iron ore. But political turmoil has unnerved investors.
The May vote is meant to complete a transition to civilian rule after a 2008 military coup, thereby unlocking hundreds of millions of dollars in European aid.
Conde's government met an opposition delegation on Monday to try to resolve the dispute - though the main opposition leaders did not attend the meeting in protest at security forces' use of violence.
Government spokesman Damantang Albert Camara said authorities had offered to allow civil society groups and foreign diplomats to act as independent observers of the electoral process.
"The opposition should accept that as a guarantee," he said, referring to the observers. "We hope the opposition's demands are not just a way of dodging the discussion. That would really be a pity."
The opposition has demanded the government replace the South African firm Waymark, saying there were irregularities when it was awarded a contract to update the electoral register. Activists also want the right to vote for Guineans overseas.
"We do not agree with the framework we are being offered," said opposition spokesman Aboubacar Sylla. "We want the activities of the Independent National Electoral Commission (CENI) to be frozen immediately so the conclusions of this dialogue can be applied."
Behind Guinea's political feuding there is a deep-rooted rivalry between the Malinke and the Peul, its two largest ethnic groups. The Malinke broadly support Conde, who comes from that ethnic group, while the opposition draws heavily from the Peul.