Security forces in the West African country of Guinea have fired tear gas to disperse opposition protesters angry over the date designated by the government for legislative elections.
President Alpha Conde last week declared the vote would be on 30 June.
He did so without agreeing to opposition demands that the government allow the mostly pro-opposition diaspora to take part in the vote.
The long-awaited election has been the cause of several violent protests.
The government has not so far commented on Thursday's violence but it earlier said it would not tolerate violence during the protests, nor be swayed by opposition threats.
The opposition argues that the date for the vote has been unilaterally determined by the president who they say has plans to rig the outcome.
Demonstrators hurled stones at security forces in the capital, Conakry, witnesses told the Reuters news agency. They responded by firing tear gas along one of the seaside capital's main highways, injuring at least three people including one protester who was shot in the chest.
"There are gendarmes and police on every intersection," Souleyman Bah, a resident of the opposition stronghold of Bambeto, told Reuters.
Correspondents say that Conakry was enveloped by smoke as protesters armed with clubs and sticks burned tyres and debris.
The election, originally earmarked for 2011, is meant to complete Guinea's transition to civilian rule following a military coup in 2008 and could unlock hundreds of millions of dollars in European aid.
Guinea is the world's top bauxite exporter, but long-term instability has dried up investment in its huge and untapped reserves of gold, iron ore and diamonds.