|The president's departure has failed to quell unrest in Tunisia [Reuters]
Soldiers have been deployed on the streets of Tunisia amid chaotic scenes following the popular ousting of Zine El Abidine Ben Ali, the president.
Troops were patrolling Tunis, the capital, on Saturday and a state of emergency was in force after Ben Ali, president for more than 23 years, fled the country in the wake of widespread protests.
The main train station in Tunis has been torched, while gunfire was heard as soldiers intervened in attempts to stop looting in the city.
The Reuters news agency reported that squads of men in civilian clothes were driving through Tunis at high speed, shooting randomly at buildings and people.
Soldiers and plainclothes security personnel dragged dozens of suspected looters out of their cars at gunpoint and took them away in lorries, according to a report from the AFP news agency.
"The army is all over the place in Tunis, they are trying to check cars and control people going by," Youssef Gaigi, a blogger and activist based in Tunisia, said.
There are fears that some of the violence is being carried out by a armed factions allied to Ben Ali, with Reuters quoting an unnamed military source as saying: "Ben Ali's security is behind what is happening."
Gaigi, who had been part of the protests that brought down Ben Ali, indicated that the army's presence was required because the police force had broken down.
"Several militias, which are actually doing some of the looting are part of the ministry of the interior, or police members, and they are co-ordinated by heads of police and intelligence in Tuisia," he said.
"We heard the army have captured some of these people but there is still a lot of work to be done."
Reports on Saturday said that General Ali Seryati, a senior advisor to Ben Ali and the former head of his security, had been seized by civilians.
Elsewhere in Tunisia, dozens of inmates at a prison in Monastir, eastern Tunisia, were killed when a prisoner started a fire at the facility.
Witnesses told Al Jazeera that other prisoners had escaped and reports said that some prisoners had been shot as they made their escape bid.
Breakouts were also reported at three other prisons and a report from The Associated Press news agency said that an official at one facility had let 1,000 inmates escape following protests at the prison.
Amid the turmoil, Tunisians have organised themselves to protect their neighbourhoods, Amine Ghali, a democracy advocate in Tunisia, told Al Jazeera.
"There is a serious security issues, but people are getting organised. They are standing in front of their neighbourhoods, forming neighbourhood committees ... they are trying to be as calm as possible and trying to help the military," he said.
In the past month, protests have swept across the country over unemployment, food price rises and corruption.
Ben Ali conceded power on Friday after a giant rally against him in Tunis but his departure, a key demand of the demonstrators, has failed to calm the unrest.
Public television station TV7 broadcast phone calls from residents of working-class neighbourhoods on the capital's outskirts who described attacks on their homes by knife-wielding assailants.
Thousands of tourists have been evacuated from the Mediterranean nation following the unrest.
The president fled to Saudi Arabia amid the protests and Fouad Mebazaa, the speaker of the lower house of parliament, has taken over as caretaker president.
Arab nations have been largely silent on the Tunisian protests, but the Arab League on Saturday released a statement calling for calm an unity in the country.
"These are historic events by any standard," Hesham Youssef, the chief of cabinet for the Arab League's secretary-general, told Al Jazeera.
"The important thing is that the current period will be a transition period, and we hope that the political forces in Tunisia will unite in the call for change in order for them to have elections as soon as possible, in order to move ahead."
Source: Al Jazeera and agencies