The mutineers seized weapons from two police stations in the country`s second city, Bouake, and took up positions at its entry points, according to reports.
Gunfire has also reportedly been heard in western Daloa town.
Ivory Coast`s President Alassane Ouattara took power in 2011 at the end of a civil war.
Bouake was at the centre of the rebellion to oust his predecessor, Laurent Gbagbo, who is on trial at the International Criminal Court on charges of war crimes.
A teacher in Bouake, Ami Soro, told Reuters news agency the city was deserted.
"Men in balaclavas are patrolling the city on motorcycles or in cars. They aren`t attacking residents... They told us to stay at home," she is quoted as saying.
The reason for the unrest is unclear, but the soldiers appear to be protesting over pay, AFP news agency reports.
"It`s a mutiny by former fighters integrated into the army who are demanding bonuses of 5 million CFA francs ($8,000; £6,500) each plus a house," a soldier who asked to remain anonymous told AFP.
An MP for Bouake, Bema Fofana, told the BBC that the soldiers did not appear to have a leader or spokesman, making it difficult to negotiate with them.
Most of the soldiers were former rebels who were integrated into the army after the civil war, he added.
The rebels swept into the main city Abidjan from their stronghold of Bouake in 2011, helping Mr Ouattara take power.
Ivory Coast`s Bouake and Daloa hit by shooting
06 January 2017
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Gunfire has been heard in two cities in Ivory Coast in a suspected mutiny by soldiers, military sources and local residents say.
