|Some Tunisians have taken local security into their own hands following the end of Ben Ali's rule [AFP]
Looting, deadly prison riots and street chaos have engulfed Tunisia after mass protests forced its long-time president, Zine El Abidine Ben Ali, to flee.
On Sunday, the AFP news agency reported that a member of the president's extended family had reportedly died of a knife wound two days earlier.
Imed Trabelsi, a nephew of Ben Ali's wife, died has he was being treated in a military hospital in the capital, Tunis, a staff member told the AFP. He was the first person in the president's extended family to die as a result of the uprising.
Trabelsi was an influential businessman and became more widely known after he was mentioned in a US diplomatic cable released by WikiLeaks that said he was reported to have stolen a yacht belonging to the chairman of the powerful French financial firm Lazard.
A new interim president, the speaker of parliament, was sworn in on Saturday, and promised to create a unity government that could include the long-ignored opposition. It was the second change of power in the North African nation in less than 24 hours.
Amid the political instability, looters emptied shops and torched the main train station in the capital, Tunis, and soldiers traded fire with assailants in front of the interior ministry.
Troops were patrolling the capital on Saturday and a state of emergency was in force after Ben Ali, president for more than 23 years, fled to Saudi Arabia in the wake of the deadly protests.
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.
Black smoke billowed over a giant supermarket in Ariana, north of the capital, as it was torched and emptied.
Soldiers fired warning shots in vain to try to stop the looters, and shops near the main bazaar were also attacked.
Some rioters appeared to be targeting businesses owned by members of Ben Ali's family. In Tunis, a branch of the Zeitouna bank founded by Ben Ali's son-in-law was torched, as were vehicles made by Kia, Fiat and Porsche - carmakers distributed in Tunisia by members of the ruling family.
Public television station TV7 broadcast phone calls from residents on the capital's outskirts, describing attacks by knife-wielding assailants.
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 issue, 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.
Residents of some Tunis neighbourhoods set up barricades and organised overnight patrols to deter rioters. In El Menzah neighbourhood, dozens of men and boys armed with baseball bats and clubs were taking turns on patrol - just as a broadcast on Tunisian television had urged citizens to do.
"This isn't good at all. I'm very afraid for the kids and myself," Lilia Ben Romdhan, a mother of three in outer Tunis," said.
There are fears that some of the violence is being carried out by 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."
In a sign that Ben Ali's rule was over, workers were taking down a portrait of the former president outside the headquarters of his RCD party on Mohamed V Avenue in the centre of Tunis.
Meanwhile, a fire on Saturday at a prison in the Mediterranean coastal resort of Monastir killed 42 people, coroner Tarek Mghirbi told The Associated Press news agency.
Witnesses told Al Jazeera that other prisoners had escaped and reports said that some prisoners had been shot as they made their escape bid.
In Mahdia, further down the coast, inmates set fire to their mattresses in protest. Soldiers opened fire, killing five inmates, a local official said.
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.
Thousands of tourists have been evacuated from the Mediterranean nation following the unrest.