Clashes broke out Wednesday in central Tunisia between police and demonstrators protesting economic hardship, as discontent mounts over new taxes and government failure to improve living conditions, three years after the revolution.
Dozens of protesters tried to force their way into the offices of the ruling Islamist party Ennahda in the town of Kasserine, but police drove them back with teargas, an AFP journalist reported.
In the village of Thala, which lies in the Kasserine region and had already witnessed clashes on Tuesday evening, protesters attacked a police post, partially burning it and driving away the security forces, witnesses said.
The region is one of the poorest in Tunisia and was a hotbed of unrest during the January 2011 revolt that toppled veteran strongman Zine El Abidine Ben Ali.
Shops and public offices remained closed in Kasserine Wednesday, as hundreds protested in the streets. They shouted slogans including "The people want the fall of the regime," the rallying cry of the Arab Spring.
Tunisia's powerful UGTT trade union confederation called the strike to coincide with the anniversary of the first death in the town during the revolution.
Central Tunisia has long suffered from neglect and a lack of opportunity, which were driving factors behind the popular uprising that began in nearby Sidi Bouzid, when a young street vendor set himself on fire in protest at his impoverished circumstances.
"On this day, which marks the death of the first martyr of the revolution in Kasserine, we wanted to protest against underdevelopment and the poor economic situation," trade unionist Sadok Mahmoudi told AFP.
"The political class must know that we remain committed to the goals of the revolution -- dignity, freedom and work."
Strikes and demonstrations have been on the rise in Tunisia since the autumn, fuelled by the persistent economic malaise and a political crisis triggered by the murder of an opposition politician in July.
In recent days, protests have taken place across the country to denounce a new tax imposed on certain vehicles that came into force this year, with numerous roads blocked by demonstrators.
On Wednesday, Ennahda expressed "understanding" towards the protest movements, and called for the cash-strapped government to reconsider the new taxes.
The latest social unrest comes as Ennahda and the opposition are locked in tense parliamentary sessions to ratify the long-delayed new constitution before a deadline of January 14. That is the third anniversary of the triumph of Tunisia's uprising, which touched off the Arab Spring.