Tunisian President Zine al-Abidine Ben Ali has fled with his family to Saudi Arabia, after being forced from office after 23 years in power.
The 74-year-old leader conceded power after protests over economic issues escalated into rallies against him.
Prime Minister Mohammed Ghannouchi has taken over as interim president, and a state of emergency has been declared.
Mr Ghannouchi has said he will meet political leaders on Saturday in an attempt to form a government.
Dozens of people have died in recent weeks as unrest has swept the country and security forces have cracked down on demonstrations over unemployment, food price rises and corruption.
After abandoning power in Tunis, Mr Ben Ali boarded a plane with his family and left the country, amid widespread speculation about where he was travelling to.
French media reported that President Nicolas Sarkozy had rejected a request for his plane to land in France.
A Saudi palace statement later said Mr Ben Ali had arrived in the country early on Saturday.
"Out of concern for the exceptional circumstances facing the brotherly Tunisian people and in support of the security and stability of their country... the Saudi government has welcomed President Zine al-Abidine Ben Ali and his family to the kingdom," the statement said.
An overnight curfew was lifted on Saturday morning, but AFP news agency reported that central Tunis remained deserted after a night of looting in several suburbs.
Earlier Mr Ghannouchi said his priority was to restore security, in the face of looting and robberies.
"I salute the fact that groups of young people have got together to defend their neighbourhoods but we can assure them we will reinforce their security," he said.
"We are at the service of the Tunisian people. Our country does not deserve everything that is happening. We must regain the trust of citizens in the government," he added.
However, it is not yet clear whether protesters will accept Mr Ghannouchi's interim leadership, or take to the streets for further demonstrations.
The BBC's Wyre Davies in Tunis said many protesters had ignored the curfew to celebrate on the streets on Friday evening.
Our correspondent says they will now want to see the fruits of their demonstrations, and will not settle for the elite remaining in power.
Mr Ghannouchi, a 69-year-old former finance minister who has been prime minister since 1999, has said he will meet representatives of political parties on Saturday to form a government, calling it a "decisive day".
He said he hoped the new government would "meet expectations".
The wave of protests began in mid-December after an unemployed graduate set himself on fire when police tried to prevent him from selling vegetables without a permit. He died in early January.
Demonstrations came to a head on Friday as thousands of people gathered outside the interior ministry, a symbol of the regime, and many climbed onto its roof. Police responded with volleys of tear-gas grenades.
President Ben Ali, who had already promised to step down in 2014, dissolved his government and the country's parliament, and declared a state of emergency.
The state of emergency decree bans gatherings of more than three people and imposes a night-time curfew. Security forces have been authorised to open fire on people not obeying their orders.
UK travel agents have scrambled to pull hundreds of tourists out of the country, and companies including Thomson, First Choice and Thomas Cook have cancelled flights scheduled to leave for Monastir on Sunday.
The UK, the US and France are among the countries advising against non-essential travel to Tunisia.
Mr Ben Ali, 74, was only Tunisia's second president since independence from France in 1956. He was last re-elected in 2009 with 89.62% of the vote.