TUNIS – At least one man has been killed in clashes with police in a Tunisian provincial town, a hospital source and witnesses told Reuters, in the latest in a series of riots across the north African country. Officials declined a request to comment on the latest clashes, which witnesses said took place on Saturday in Thala, about 200 km (125 miles) southwest of the Tunisian capital and near the border with Algeria. Riots have been breaking out in towns and cities across Tunisia for nearly a month. Protesters say they want jobs and investment, but Tunisian officials say the unrest is the work of a minority of extremists set on damaging the country. An employee at a hospital in Thala, who spoke on condition of anonymity, said several people had been admitted to the hospital after the clashes. "At least one was killed," the source said. People who said they witnessed the clashes, local trade union sources and neighbours of the victims, also told Reuters by telephone from Thala that at least one person died after being shot in the confrontation. Witnesses said police fired their weapons after using water cannon to try to disperse a crowd which had set fire to a government building and threw stones and petrol bombs at police. Separately, witnesses in the nearby town of Gassrine, the provincial center, told Reuters by telephone there were violent clashes there as well and that a number of people had been hurt. Tunisian President Zine al-Abidine Ben Ali has said the violent protests are unacceptable and could harm Tunisia's interests by discouraging investors and tourists who provide a large part of the country's revenues. Tunisian authorities say police have used force only where necessary to stop protesters endangering life and ransacking government buildings. The United States said on Friday it had called in Tunisia's ambassador in Washington to express its concern about the protests Protests traditionally have been rare in Tunisia, which has had only two presidents since independence from France 55 years ago. The country has in the past been praised by Western allies as a model of stability and prosperity in the Arab world.