Heavy gunfire was heard in the commercial capital Abidjan, causing panic among residents.
The unrest began after a spokesman for the soldiers announced on Thursday that they had dropped their pay demands.
The mutineers, most of whom are former rebels, are revolting over delayed bonuses promised by the government.
In January, they forced the government into paying them about $8,000 (Â£6,200). They were due to receive a further payment this month.
On Friday, shots were fired in the air at the bases in Abidjan, Bondoukou in the east, BouakÃ© in the centre, and Korhogo in the north.
The BBC's Tamasin Ford reports that she witnessed a scene of panic in Plateau, Abidjan's financial district.
It is believed the mutineers were firing blanks.
In response, elite Republican Guard troops in Abidjan fired warning shots that pushed the mutineers back the inside the military headquarters compound in Abidjan, Reuters reports.
About 8,000 mutineers are unhappy that they were not consulted ahead of Thursday's TV ceremony in which their spokesman said the pay demand had been dropped.
Reacting to the spreading unrest, President Alassane Ouattara held an emergency meeting of the country's security council.
The mutiny raised fears of a resurgence of the violence seen during Ivory Coast's 10-year civil war, which ended in 2011.
Some of the mutineers were thought to be former rebels who joined the army after the conflict.
Soldiers at a number of Ivory Coast's military bases have been firing into the air and blocking streets in several cities in protest over a pay dispute.