At least six people were injured in the Guinean capital on Thursday in clashes between protesters, security forces and government supporters that threaten to derail a planned meeting between the president and leader of the opposition.
President Alpha Conde has invited Cellou Dalein Diallo to talks on Friday. An opposition spokesman this week said Diallo was ready to meet with Conde, after rejecting earlier overtures.
But Diallo said on Thursday he had been prevented from leaving his home by security forces posted outside the entrance.
"With what happened, we will need to discuss and see if it is even worth responding to the president's invitation (Friday)," he told a local radio station.
Meanwhile, youths in Conakry blocked roads with burning tyres and drove back police in some neighbourhoods in the latest unrest over the timing of elections.
Residents reported hearing gunfire in the capital city's Sonfonia neighbourhood, and a government statement said two of those hurt had been shot. In a later statement, it said two of the six injured were gendarmes, and 19 people were arrested during the violence which caused material damage and led to over 100 school closures.
Witnesses said police fired tear gas in the Bambeto and Cosa neighbourhoods to disperse demonstrators.
"Counter-protesters also clashed with the opposition demonstrators, throwing projectiles," one Conakry resident said.
The opposition says a decision announced in March to hold Guinea's presidential election on Oct. 11 broke a 2013 agreement to stage long-delayed local elections first.
Analysts say holding local elections first would give Conde's rivals more influence in organising the presidential polls.
Deputy government spokesman Moustapha Naite called Thursday's violence "regrettable".
"At a moment when we are holding out our hand, such incidents should not be happening. Nevertheless, the government remains willing to talk to find a solution," he told Reuters.
The demonstrations, which began in mid-April in Conakry and other towns in the West African country, have left at least five people dead and many more injured, according to opposition leaders, who say security forces have fired live rounds during clashes.
The government says four have died and rejects accusations that shots have been fired at protesters. Authorities say police officers have been shot at during the demonstrations.