Tunisia's government ordered the indefinite closure of all schools and universities on Monday after clashes with police which killed 14 civilians at the weekend.
Facing the worst unrest for decades, the government deployed the military onto the streets in the worst-hit areas late on Sunday and that appeared to have had an effect, with fewer clashes and no new deaths reported.
But witnesses in two provincial towns said police fired into the air to disperse crowds after funeral processions for people killed in clashes with police in the past two days turned into angry confrontations.
President Zine al-Abidine Ben Ali, who has been in office since 1987, sounded a defiant note in a televised address, saying the rioting was a "terrorist act" orchestrated by foreign parties trying to damage Tunisia.
Students were among those taking part in the riots and on Monday a Reuters reporter in the capital, Tunis, said riot police had surrounded a university campus to stop hundreds of students who were trying to protest in the street outside.
Most of the unrest has so far been limited to provincial towns, with the Mediterranean port city of Tunis largely unaffected.
"Following violence in universities and lycees ... we have decided to stop all the lessons in all educational establishments," the official TAP news agency quoted the Education Ministry as saying.
In his television address, Ben Ali said urgent measures would be taken to create more jobs -- a major grievance behind the riots -- but violence would not be tolerated.
"The events were the work of masked gangs that attacked government buildings at night and even civilians inside their homes in a terrorist act that cannot be overlooked," he said.
"The events are being managed by foreign parties that do not want what is good for the country ... Justice has taken its course to investigate the circumstances of the events and determine responsibility."
Local people told Reuters there was rioting in Bizerte, a town on the Mediterranean coast that throngs with tourists in the summer. It was the first case of unrest reaching Tunisia's more prosperous coastal holiday resorts.
Several hundred youths damaged a labour exchange, set fire to a bank and burned several vehicles including a police car, four witnesses told Reuters.
In the inland provincial towns that were the scene of many of the deaths at the weekend, there was renewed confrontation though not on the scale of previous days, witnesses said.
In the town of Gassrine, about 200 km (125 miles) southwest of the capital, a witness said a funeral procession for civilians killed at the weekend turned into a confrontation.
"Police opened fire into the air," Mohamed Ali Nasri told Reuters by telephone from the scene.
In the town of Rgeb, witnesses said funeral processions for people shot in earlier clashes also turned violent.
"The town is encircled by the police. There are 2,000 protesters in a confrontation throughout the town with the police, who are using teargas and are opening fire," Kamel Labidi, who said he was at the scene, told Reuters by telephone.
Tunisian authorities could not immediately be reached to comment on the latest clashes.
In the towns of Thala, Gassrine, Seliana, Rgeb and Meknassi army trucks were sent in to reinforce police, residents said.
"Calls for restraint"
In New York, the United Nations said Secretary-General Ban Ki-moon was concerned about the escalation of violence and called for restraint. The European Union, Tunisia's biggest trade partner, said it deplored the loss of life.
A statement from the UN chief's office said he was concerned about the escalation of violence.
"The Secretary-General calls for restraint and urges all parties to seek to resolve differences through dialogue. He underscores the importance of full respect for freedom of expression," it said.
Washington has already expressed concern about the Tunisian government's handling of the protests.
In a sign it would stand up to international criticism, the Tunisian Foreign Ministry said on Monday it had summoned the U.S. ambassador to Tunis to express its "astonishment" at Washington's stance, state-run television reported.
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