It was the second change of power in this North African nation in less than 24 hours.
Amid the political instability, looters emptied shops and torched the main train station in Tunis, soldiers traded fire with assailants in front of the Interior Ministry, and thousands of European tourists sought a plane flight home.
The death toll mounted. At least 42 people were killed Saturday in a prison fire in one resort town and the director of another prison in another tourist haven let 1,000 inmates flee after soldiers shot five dead amid a rebellion. Those deaths came on top of scores of others after a month of protests in which police often fired upon demonstrators.
After 23 years of autocratic rule, President Zine El Abidine Ben Ali abruptly fled the country Friday for Saudi Arabia following mass street protests over corruption, a lack of jobs and clampdowns on civil liberties.
The leadership changes then came at a dizzying speed.
Ben Ali's longtime ally, Prime Minister Mohammed Ghannouchi, stepped in briefly with a vague assumption of power that left open the possibility that Ben Ali could return. But on Saturday, the head of the Constitutional Council declared the president's departure permanent and gave Fouad Mebazaa, leader of the lower house of parliament, 60 days to organize new elections.
Hours later, Mebazaa was sworn in.
In his first televised address, the interim president asked the premier to form a "national unity government in the country's best interests" in which all political parties will be consulted "without exception nor exclusion."
The move was one of reconciliation, but it was not clear how far the 77-year-old Mebazaa, who has been part of Tunisia's ruling class for decades, would truly go to work with the opposition. It was also unclear who would emerge as the country's top political leaders, since Ben Ali utterly dominated politics, placing allies in power and sending opponents into jail or exile.
On the streets, the unrest was frightening.
A fire Saturday at a prison in the Mediterranean coastal resort of Monastir killed 42 people, coroner Tarek Mghirbi told The Associated Press. The cause of the fire was not immediately clear.
In Mahdia, further down the coast, inmates set fire to their mattresses in protest. Soldiers opened fire, killing five inmates, top local official said. The director of the prison then let about 1,000 other inmates flee the prison to avoid further bloodshed, the official said, asking not to be identified because of security concerns.
In front of the Interior Ministry in Tunis, the capital, security forces and unidentified assailants had a shootout Saturday that left two bodies on the ground.
Sporadic gunfire echoed around the capital and looters were out in force. 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, which had financial interests in a wide range of sectors, from banking to car dealerships. 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.
Residents of some Tunis neighborhoods set up barricades and organized overnight patrols to deter rioters. In the tony El Menzah neighborhood, 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," said Lilia Ben Romdhan, a mother of three in outer Tunis. "If (Ben Ali) had stayed in the country it would be better."
Kamel Fdela, selling oranges and bananas in the same neighborhood, said he wanted democracy but was not sure that would happen. He also feared food shortages, with so many stores closed and others looted.
"God willing, a real man will take over," he said.
Tunisian airspace reopened Saturday, but some flights were canceled and others left with delays. Thousands of tourists were still being evacuated from the Mediterranean nation known for its sandy beaches, desert landscapes and ancient ruins.
"It was quite scary but I was never in fear for my life," said Mary Grist, a retiree who arrived Saturday at Britain's Manchester Airport from Tunisia. "What we have seen is the aftermath, burned-out petrol stations and the army lining the streets with their guns."
A Paris-based photographer, Lucas Mebrouk Dolega of the EPA photo agency, was in critical condition Saturday after being hit in the face by a tear gas canister.
Tunisians abroad celebrated Ben Ali's ouster.
Thousands of messages congratulating the Tunisian people flooded the Internet on Twitter, Facebook and blogs. Hundreds demonstrated Saturday afternoon in Brussels, demanding that Ben Ali be brought to justice. One banner read "Ben Ali has to pay for his crimes."
Another 8,000 people marched in Paris to express support for Tunisia's people, waving Tunisian flags and carrying cardboard coffins to honor those killed. They hailed the "Jasmine Revolution," referring to the scented flower that is omnipresent in Tunisia.
"I went to the march to celebrate but also to express my solidarity with the Tunisian people, who have suffered so much," said Paris marcher Ghazi Zouari, a 42-year-old Tunisian who has lived in France for decades. "It was a celebration, but tinged with fear, because the situation on the ground is so unstable."
Saudi King Abdullah's palace confirmed that the ousted president and some family members had landed in Saudi Arabia, saying the kingdom welcomed him with a wish for "peace and security to return to the people of Tunisia."
A source inside the kingdom who spoke on condition of anonymity said Ben Ali was in the small city of Abha, about 310 miles (500 kilometers) south of Jeddah.
The French government, meanwhile, said other members of Ben Ali's family were "not welcome" in the former colonial ruler and were planning to leave.
Ben Ali's downfall sent a warning to other autocratic leaders across the Arab world, especially because he did not seem especially vulnerable until the very end and managed his country of 10 million better than many other Middle Eastern nations.
He turned Tunisia into a beach haven for European tourists, an area of stability in volatile North Africa. Residents had a lack of civil rights and little freedom of speech, but a better quality of life than in neighboring Algeria or Libya.
Ben Ali presided over reforms to make the economy more competitive and growth last year was 3.1 percent. Unemployment, however, was officially 14 percent but believed to be far higher among the young.
The riots started after an educated but jobless 26-year-old committed suicide in mid-December when police confiscated the fruits and vegetables he was selling without a permit. His desperate act hit a nerve, sparked copycat suicides and focused anger against the regime into a widespread revolt.
In Egypt, human rights activist Hossam Bahgat said he was glued to the news watching the fall of the Tunisian government and hoped that his countrymen could do the same someday.
"I feel like we are a giant step closer to our own liberation," he told the AP. "What's significant about Tunisia is that literally days ago the regime seemed unshakable, and then eventually democracy prevailed without a single Western state lifting a finger."