At least 41 people have been injured in clashes in Guinea between police and opposition protesters demanding long-delayed parliamentary elections.
A total of 24 protesters were hurt in Thursday's riots, including one in a serious condition after being shot, hospital sources said, while 17 police officers were injured by missiles, according to local television reports.
Alhassane Conde, the country's interior minister, speaking on television late on Thursday, said anyone continuing the protests on Friday would "find themselves up against the state".
The clashes followed an opposition call on Monday for a national protests demanding talks with President Alpha Conde's government on holding elections and for an audit of the voter roll.
"Today Guineans are speaking out against President Alpha Conde's desire to rig the legislative elections, which he won't be able to win transparently," said Cellou Dalein Diallo, the main opposition leader.
Conde's government has long delayed polls, which, according to the country's constitution, were to be held within six months of his inauguration in December 2010 as head of a transitional council tasked with overseeing the move from military to civilian rule.
The government had promised elections for July 8, but in April they were postponed as Conde said there were "technical problems" that had not been resolved.
Protests paralysed Conakry from mid-morning to late afternoon, as police and protesters had a series of clashes along the rally's route.
Security forces fired tear gas and beat people back with their batons as they tried to prevent youths from passing in front of the ruling party headquarters in the Hamdallaye suburb, an AFP news agency journalist said.
"We've received 15 who were wounded in the opposition protest. They were all hit with rifle butts," Ibrahima Balde, head of a Conakry clinic, said.
Balde said some of the wounded had lost consciousness inside the clinic and could have neurological complications.
A doctor at Donka public hospital said staff had treated and released four people, all injured by baton blows.
At another clinic an official said five injured people had been admitted, including one seriously injured by a bullet which hit his spinal column.
The protests reflect rising public anger, Sydia Toure, another opposition leader, said.
"Guinea doesn't belong to just one individual, it belongs to more than 12 million people."
Most shops, schools and petrol stations kept their doors closed on Thursday, fearing violence, and security forces maintained a strong presence, especially around the headquarters of the national election commission (CENI).
CENI has been accused by the opposition of being biased towards the ruling party, Rally for the Guinea People (RPG).
The RPG urged the opposition to "banish violence," saying it was important to organise the elections peacefully.
The European Union has warned it will not release any aid to the country without democratic polls.
The last legislative polls were held in June 2002 during the regime of President Lansana Conte, who died in December 2008 after 24 years in power.