Ivory Coast's government on Wednesday pleaded for calm as deadly protests by angry security forces and troops spread across the country, shutting down the main port of Abidjan.

In a bid to quell the rising unrest, which on Tuesday left four soldiers dead, the government pledged to improve the troops' livelihoods.

"Nothing can be done so long as there is chaos," Interior Minister Hamed Bakayoko said after a cabinet meeting over the crisis.

He called the growing tension "alarming", adding that he feared a "contagion" as more troops joined the revolt.

A mutiny among troops over pay erupted on January 5, stoking security fears in the world's top cocoa producer.

Initial protests were quelled when mutineers reached a deal with the government -- but more soldiers have since Tuesday taken to the streets of the west African country demanding similar bonuses.

While the first wave of protests did not cause any fatalities, four soldiers were killed on Tuesday in the administrative capital Yamoussoukro, the government said.

With tension spreading, soldiers and members of the security forces fired shots in the air in Abidjan, the economic capital, and second city Bouake on Wednesday.

Abidjan port, one of Africa's biggest, was closed Wednesday when angry security forces began firing in the air, port staff said.

However the port's management swiftly issued a statement saying that security measures were being implemented to allow operations to resume.

In Bouake, prison guards also staged protests to show their anger, reported an AFP correspondent.

"We cannot accept that part of our army benefits from a bonus of 12 million CFA francs (18,000 euros, $19,000) while others do not. That's why we are shooting in the air," a Bouake prison guard said on condition of anonymity.

- 'Act of anger' -

"Worrisome," screamed the headline of local newspaper Le Patriote. The subheading branded the soldiers' protests an "act of anger".

Several mutinous troops have told AFP that under a deal reached last week, 8,500 troops were promised 12 million CFA francs each. The government has refused to disclose any figures.

Five million CFA francs are due to be delivered by February 5, although it is unclear how the government intends to finance the payments.

According to a statement, the government sought to justify its concessions by saying it in fact owed the mutineers payments in delayed bonuses and salaries.

"The president (Alassane Ouattara) has instructed all the top commanders to begin meetings with all our security forces," the government statement said.

The authorities sought to assure the forces "of the will to improve their living conditions," the statement added.

- 'Trembling with fear' -

But with no solution yet in sight, civilians in Ivory Coast feared a return of unrest.

"We are trembling with fear," said Rachel Kouame, 27, a seamstress in Yamoussoukro.

Kone, the manager of a phone booth, agreed: "There is a heavy mood with the military patrols."

This is not the first crisis involving Ivory Coast's military in recent years.

Bouake, which is home to 1.5 million people, was the cradle of a rebellion in 2002, in a failed attempt to oust then-president Laurent Gbagbo.

The revolt sliced the former French colony into a rebel-held north and government-controlled south, triggering years of unrest.

Ivory Coast has long been west Africa's star economic performer. But when Gbagbo refused to step down despite an election defeat in 2010, 3,000 people were killed in months of conflict.

Later, in 2012, rebels-turned-soldiers protested in Bouake and Abidjan, and briefly brought the country to a standstill.

The government then agreed to a deal that provided amnesty for the mutineers and a financial settlement.

- Waves of unrest -

With a 10-percent yearly economic growth rate, the west African country is now back on the rails.

The International Monetary Fund said last month that Ivory Coast was on track towards becoming the continent's fastest-growing economy.

The latest mutiny, however, has raised fears the country might slip back into deadly unrest.

In 2016, Ivory Coast approved an ambitious military planning budget seeking to modernise the army and aid in buying new equipment for 1.2 billion euros (1.25 billion dollars).

Now the government could have to delve into those funds to finance the payments of mutinous troops.

However, it wouldn't have enough to offer those payments to all of its security forces, about 15,000 additional troops.