The unrest erupted in the early hours of Friday morning with troops demanding hefty pay rises.
Ivory Coast's defence minister on Saturday headed to the northern city of Bouake where troops have seized control, firing rocket launchers in the streets in an angry protest over pay.
As the country's second city, Bouake was the headquarters of an armed rebellion that broke out in 2002 and split Ivory Coast in two until 2011.
The unrest erupted in the early hours of Friday morning with troops demanding hefty pay rises, and the protests quickly spread to other cities, including Man in the west.
"We are going to talk with our men, hear their complaints and find solutions to this situation that is understandable but regrettable," Defence Minister Alain-Richard Donwahi said in a televised address before his departure.
The rattle of automatic gunfire continued throughout the night, and could still be heard on Saturday morning along with the sound of heavy weapons fire, local residents and an AFP correspondent said.
"We heard shooting all through the night," one resident told AFP by phone.
Troops had also set up barricades, blocking entry into the city where long queues of vehicles could be seen waiting.
Similar protests erupted in several central and northern towns throughout the day and by Saturday morning, the unrest had also spread to Man, witnesses and a military source said.
"I went out of my house at 7:00 am when I heard the first shots," a local resident called Jean told AFP, saying that within an hour, the firing had "intensified."
"The military is now parading through the streets in vehicles," he said, with a military source confirming the unrest had hit the city shortly after dawn on Saturday.
The protests had also spread to the central towns of Daloa and Daoukro as well as Korhogo in the north, where angry troops demanded salary hikes although witnesses said they had largely disappeared from the streets by Friday evening.
Speaking to AFP on Friday, a military official said the unrest was spearheaded by former rebel fighters now integrated into the army who were demanding bonuses of five million CFA francs ($8,000, 7,600 euros) each plus a house.
"We are emerging from a crisis and our army is being rebuilt," the defence minister said in his televised address.
"Things are not moving as quickly as we hoped but they are moving none the less."
Ahead of the minister's arrival, troops expressed wariness over his intentions, with one telling AFP, "We believe they are getting ready to do something against us."
"If he wants to come to negotiate, there won't be any problems. But if they want to attack us, we are ready for that too," he added.
President Alassane Ouattara, who is currently in Ghana for the swearing in of the country's new president, was expected to return to Abidjan, the economic capital, by the end of the day for a cabinet meeting.
Friday's unrest saw troops breaking in to Bouake's main weapons depot, arming themselves with rocket-launchers and other weapons mounted on pickup trucks, a military source said.
Troops then attacked all seven police posts, manned strategic junctions and put up barricades in the town centre, an AFP correspondent said.
A similar dispute by rebels-turned-soldiers erupted in Bouake in November 2014 which spread to Abidjan and briefly brought the country to a standstill.
The nearly 9,000 strikers, who joined the army between 2009 and 2011, were demanding full payment of back pay and promotions.
Bouake was the capital of a rebellion which erupted in 2002 in a failed attempt to oust then president Laurent Gbagbo, who remained in power.
The effective partitioning of the country between a rebel-held north and a loyalist south sparked a decade of clashes and crises.
Rebel forces generally backed Ouattara, the current president who took office in April 2011 after a bloody post-electoral showdown which ended with Gbagbo's arrest.
Gbagbo was turned over to the International Criminal Court in The Hague, where his trial began in January last year for crimes against humanity.