Thousands of demonstrators from all walks of life mobbed the capital of Tunis to demand Ben Ali's ouster, the culmination of weeks of protests that have swept the country. Prime Minister Mohammed Ghannouchi went on state television to announce that he is assuming power in this North African nation known for its sandy beaches and ancient ruins.
The shakeup was certain to have repercussions in the Arab world and beyond _ as a sign that even a leader as entrenched and powerful as Ben Ali could be brought down by massive public outrage.
The president tried vainly to hold onto power amid the riots, declaring a state of emergency Friday, dissolving the government and promising new legislative elections within six months. On Thursday night he went on television to promise not to run for re-election in 2014 and slashed prices on key foods such as sugar, bread and milk.
Yet Friday produced the largest demonstrations in generations. Police repeatedly clashed with protesters, some of whom climbed the walls of the dreaded Interior Ministry, site of torture reports for years. Clouds of tear gas and black smoke hung over the city's whitewashed buildings and tour operators hurriedly evacuated thousands of tourists.
Tunisian air space was closed news reports citing unidentified government sources said Ben Ali had left the country. His plane landed in Jeddah according to Al-Jazeera TV channel.
His whereabouts were not known and the details about his removal from power were unclear. The prime minister did not say anything about a coup or about the army being in charge, saying only that he was taking over while the president is "temporarily indisposed." "I take over the responsibilities temporarily of the leadership of the country at this difficult time to help restore security," Ghannouchi said in a solemn statement.
"I promise ... to respect the constitution, to work on reforming economic and social issues with care and to consult with all the sides." The state of emergency remained in effect after the prime minister's announcement, and the streets of central Tunis fell quiet after a day of rioting and volleys of tear gas.
A black armored vehicle stood behind the Interior Ministry.
The 74-year-old leader came to power in a bloodless coup in 1987. He took over from a man called formally President-for-Life Habib Bourguiba, the founder of modern-day Tunisia who set the Muslim country on a pro-Western course after independence from France in 1956.
Ben Ali removed Bourguiba from office for "incompetence," saying he had become too old, senile and sick to rule. Ben Ali promised then that his leadership would "open the horizons to a truly democratic and evolved political life." But after a brief period of reforms early on, Tunisia's political evolution stopped.
U.S. diplomatic cables released by WikiLeaks have called Tunisia a "police state" and described the corruption there, saying Ben Ali had lost touch with his people.
Social networks like Facebook helped spread the comments to the delight of ordinary Tunisians, who have complained about the same issues for years.
Under Ben Ali, most opposition parties were illegal.
Amnesty International said authorities infiltrated human rights groups and harassed dissenters. Reporters Without Borders described Ben Ali as a "press predator" who controlled the media.
He consistently won elections with overwhelmingly questionable scores: In 2009, he was re-elected for a fifth five-year term with 89 percent of the vote. Beforehand, he had warned opponents they would face legal retaliation if they questioned the vote's fairness.
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 generalized anger against the regime into a widespread, outright revolt.
In Washington, National Security Council spokesman Mike Hammer said the U.S. government, an ally of Tunisia in the war against terror, was monitoring the developments.
"We condemn the ongoing violence against civilians in Tunisia, and call on the Tunisian authorities to fulfill the important commitments made by President Ben Ali in his speech yesterday to the Tunisian people, including respect for basic human rights and a process of much-needed political reform," he said.
With the tensions mounting, the leading tour operator Thomas Cook said it was evacuating more than 4,000 holidaymakers from the Mediterranean nation including from Germany, Britain and Ireland.
France became the latest in a list of European countries to advise its citizens against travel to Tunisia.
(Edited by Ahram Online)