Fourteen civilians have been killed in the latest of a series of riots in Tunisia, the government said on Sunday.
The civilians were killed in clashes with police in three towns.
The government said police had faced violent crowds trying to destroy public buildings, and opened fire in self-defence after shots in the air failed to stop rioters.
People taking part in the unrest, which has lasted for nearly a month, say they are angry at a lack of jobs and investment.
Officials say the rioting is the work of a minority of violent extremists intent on damaging Tunisia.
A leading opposition figure urged President Zine al-Abidine Ben Ali to order security forces to stop using fire arms.
A government said law enforcement officers were "doing nothing more than carrying out their legal and legitimate mission to maintain order and guarantee the safety and liberty of citizens."
Tunisian authorities say they have responded to protesters' grievances by launching, with employers, a programme to urgently give jobs to 50,000 unemployed graduates.
Tunisia has recorded strong economic growth in the past decade but it has not been fast enough to satisfy demand for jobs.
Unrest in the past few days in neighbouring Algeria over unemployment and food prices has killed two people and injured hundreds, officials said.
The violence in Algeria appeared to have subsided on Sunday and there was no evidence of any link to the Tunisian unrest.