Tunisian security forces fired into the air to try to disperse more than 3,000 protesters who were preparing to attack a government building in the provincial town of Kasserine On Wednesday, witnesses said.
The protesters took to the streets because they felt the country's new authorities had failed to recognise local people's contribution to a revolution earlier this year which inspired the "Arab Spring" uprisings.
The clashes underlined the tough task facing the new, Islamist-led government, elected in the country's first democratic vote last month, in meeting expectations for jobs and better living standards in poor provincial towns.
"Young men are burning tyres in the street," one resident, Bouraoui Sadaoui, told Reuters from the town, which is about 300 km (200 miles) southwest of the capital, Tunis. "They are throwing rocks and surrounding the town jail."
"They want to set fire to the prison ... The military fired into the air and are using tear gas to disperse the people," he said. "Several people have been injured by tear gas."
Tunisia became the birthplace of the "Arab Spring" uprisings in January when a wave of protests forced former President Zine al-Abidine to flee to Saudi Arabia.
The revolution set the template for uprisings in Egypt, Libya, Syria and Yemen which have re-shaped the political landscape of the Middle East.
Kasserine was one of the first towns to rise up against Ben Ali's rule. It also suffered some of the highest casualties of the revolution when Ben Ali's police opened fire on demonstrators.
The trigger for Wednesday's protest was a ceremony a day earlier to inaugurate Tunisia's new constitutional assembly in the capital.
During the ceremony the names of people killed in the revolution were read out, but residents said some of Kasserine's victims were omitted.
"The situation is serious here," a local man called Adnen Nasri told Reuters from Kasserine.
"People are very angry about how the town was marginalised by missing out the names of the town's martyrs, who were at the origins of the revolution."
"Thousands of young people are now in a stand-off with the security forces in front of the prison," he said.
Tunisia's revolution delivered democracy to a country which had lived under autocratic rule since its independence from France half a century ago.
But instead of improving living standards, as many people hoped, the revolution made the average Tunisian worse off.
Tourists, the main source of foreign revenue, and some investors were scared off by the instability that accompanied the uprising. Economic growth has slumped and unemployment is forecast to rise this year.
The moderately Islamist Ennahda party, which dominates the new governing coalition, has said it is committed to creating jobs, especially for towns like Kasserine away from the more affluent area on the Mediterranean coast.