Tunisia's main Islamist movement, Ennahda, condemned on Tuesday the latest spate of violent incidents in the country and reiterated its commitment to the electoral process.
"We condemn violence wherever it comes from, be it from demonstrators or from the security forces," the movement's chairman, Rached Ghannouchi, said at a press conference.
"Our first message is to reassure the Tunisian people: everything that happened does not jeopardise the revolution and elections will take place as planned on October 23," he said.
Ennahda supporters were among those accused of being behind a series of weekend attacks against police stations and protests against the government that left a teenage boy dead.
Ghannouchi took umbrage at comments made Monday by Prime Minister Beji Caid Essebsi, who saw the latest string of incidents as an attempt by "some parties" to destabilise the country and derail the elections.
"These accusations against forces he did not name were interpreted as being directed at Ennahda," the Islamist leader said.
Ghannouchi stressed that his movement was supportive of the security forces and insisted Ennahda never organised any protests.
Tunisia's prime minister had on Monday accused protesters who held a wave of demonstrations over the weekend of plotting to destabilise the country, six months after the revolution that inspired the Arab Spring.
One man was killed at a demonstration on Sunday when soldiers fired into the air to bring the crowd under control.
It was the first reported death in a number of violent protests that have hit Tunis and other cities since Friday.
Essebsi said the protests were intended to spread chaos in addition to derailing the elections to choose an assembly charged with drawing up a new constitution.
"There is an orchestrated plan to upset the stability of the country," he said in a televised address.
"Elections will be held as scheduled on Oct 23 despite everything," he said. "I appeal to all political parties and citizens to defend the country."
The defence ministry said the demonstrator had been killed in Sidi Bouzid, the town in central Tunisia where a young man killed himself by setting himself on fire last December, providing the spark that set off the Arab Spring revolutions now convulsing much of the region.
"One civilian was killed yesterday evening in Sidi Bouzid when soldiers fired into the air to disperse rioters who had attacked them," Colonel Marouan Bouguerra told journalists in Tunis on Monday.
The government later said it had ordered an overnight curfew on the town starting on Monday. The curfew would last from 10pm (9 pm GMT) till 5am every night until further notice.
The rioting is the starkest sign to date of the friction between Tunisia's secular establishment and Islamists who have been growing more assertive since the country's autocratic leader was ousted in a revolution six months ago.
Sunday's violence was sparked by an incident on Friday when police, trying to break up an anti-government demonstration in the centre of Tunis, fired teargas inside a mosque.
Also on Sunday about 200 youths, many of them with the beards typically worn by Islamists, set fire to a police station in the Intilaka district in the west of Tunis.
On the other hand, Radhia Nasraoui, like many Tunisians, sees the growing chaos as a sign that Ben Ali's henchmen are still pulling many strings and creeping back into the country's political life.
"They're still here, we shouldn't be surprised that horrible things are happening in Tunisia," she told AFP.
"The counter-revolutionaries have had time to regroup and they are doing everything they can to sabotage the democratic process."
Tunisians overthrew autocratic leader Zine al-Abidine Ben Ali in January in a revolution that inspired uprisings in Egypt and elsewhere.