Forces loyal to Ivory Coast’s President Alassane Ouattara have exchanged fire in the main city of Abidjan.
The incident took place between the Invisible Commandos group, which controls areas of Abidjan, and troops brought from the north of the country.
The BBC’s John James says the firing in the north of the city lasted less than 30 minutes but caused panic.
It is the most public sign yet of splits in the coalition of forces that brought Mr Ouattara to power last week.
His predecessor, Laurent Gbagbo, was captured last week by pro-Ouattara forces after refusing to step down when he lost elections in November.
Our correspondent says pockets of pro-Gbagbo militia continue to hold out in Abidjan’s western district of Yopougon, but stability is slowly returning to the city which has experienced several weeks of fierce battles.
The backbone of the Pro-Ouattara forces swept down through the country last month from their northern bases, three months into the stalemate over the election result.
They came from a group of former rebels called the New Forces, who for nearly a decade have controlled the northern half of the country.
In Abidjan, they were joined by a former rebel commander Ibrahim Coulibaly, who led the Invisible Commandos to gain control of northern parts of the city in the weeks before the main offensive against Mr Gbagbo began.
Mr Coulibaly, a former bodyguard of President Ouattara, now says he wants recognition for the role he played in overthrowing Mr Gbagbo.
But his forces are accused of being responsible for much of the widespread looting of businesses and vehicles over the past week and also of charging motorists using the road north of Abidjan, our reporter says.
In an apparently unrelated incident, there was also shooting on Wednesday in the south-western port of San Pedro in another internal dispute between pro-Ouattara forces.
The commander in San Pedro said the matter was now settled but gave no further details.
Ivory Coast is trying to restart its economy and the government says schools and banks should reopen next week.
But these incidents will add to the fear that insecurity may persist, our correspondent says.
Meanwhile, the African Union has said it is lifting its suspension of Ivory Coast and has dropped sanctions against the country.
The European Union has also eased some of its restrictions on Ivory Coast, paving the way for cocoa exports to resume.