Tunisia's military has been deployed on the streets of several cities after three nights of protests over the government's new austerity measures.
Demonstrators have clashed with security forces since Monday night after a new budget raised taxes and pushed up the cost of living.
More than 600 people have been arrested and dozens of police were injured in clashes that have spread across the country. Young men have burned tyres and hurled Molotov cocktails and stones, while police have responded with tear gas.
One man has been killed in disputed circumstances, with protesters say he was run over by a police vehicle, with the authorities claiming he may have died from respiratory problems.
The protests reflect months of frustration in a country often described as the "only success story" of the Arab Spring.
Tunisians overthrew Zine El Abidine Ben Ali, the longtime dictator, in 2011 and inspired similar uprisings in Egypt, Libya and Syria.
While the other revolutions have descended into violence or given way to authoritarianism, Tunisia's democracy has remained for the most part intact.
A secular party leads the government, in coalition with a moderate Islamist group, but in return for a loan of $2.bn (€2.4bn) from the International Monetary Fund, Tunisia has agreed to take economic measures to bring down the country's deficit.
On January 1, a new budget came into force which raised petrol prices and a series of taxes on houses, cars and other items.
Protesters took to the streets in smaller cities outside the capital Tunis. Several days of peaceful protests escalated earlier this week as youths clashed with security forces.
The government ordered soldiers on to the streets and demonstrations are expected today as Friday is the traditional day of protest in the Middle East and North Africa.
While protests were sparked by the new budget, frustrations over a lack of economic progress have been growing.
Tunisia's economy has suffered as tourists avoid the country after several terrorist attacks. Thirty-eight people, including 30 Britons, were killed at a resort near the town of Sousse in 2015. (© Daily Telegraph, London)