At least three people died and several others were injured in clashes that broke out late on Monday in southern Guinea between opposition militants and government supporters, witnesses said.
The violence in the town of Gueckedou near the border with Liberia, around 700 km (420 miles) from the capital Conakry, followed days of protests against the town's military prefect, whom the opposition accuses of abuse of power.
A police official said vehicles carrying reinforcements of police, soldiers and gendarmes left Conakry on Tuesday and were on their way to Gueckedou to try to end the violence.
"The demonstrations and counter-demonstrations led to bloody clashes last night... These people were armed with machetes, clubs, sticks and other weapons. It was very violent," another senior police officer said, asking not to be named.
Government authorities said two people were killed during the night, and several others were injured. Witnesses said the death toll was higher after the clashes continued into Tuesday.
"I personally saw three bodies. But I was told there were at least five killed," Gueckedou resident Mohamed Barry told Reuters by telephone, adding that the violence had continued into the afternoon.
"The security forces intervened, shooting in the air and throwing teargas... The city is deserted. Everyone's gone home, afraid they'll get caught up in it," he said.
Gueckedou is the hometown and stronghold of support for Jean-Marc Telliano, who was sacked as agriculture minister by President Alpha Conde in October amid public accusations of corruption in the West African country.
Following his dismissal, Telliano joined the opposition and announced his intention to return home and help defeat Conde's ruling RPG party in the next legislative elections.
"I'll go to Gueckedou whether the prefect likes it or not. If he wants a new civil war in Gueckedou, he should stop me from going," Telliano said in a radio interview on November 28.
Conde was elected president of Guinea, the world's top supplier of the aluminium ore bauxite, in late 2010. The vote ended military rule but was tainted by deadly riots and opposition complaints of fraud.
His government has been trying to organise legislative elections, the last major step in a transition back to civilian rule and a prerequisite to unlock millions of dollars in frozen aid. But progress has been slowed by opposition worries that the electoral body is biased.