A rioter chants slogans as he holds a riot police shield during clashes with the police in downtown of the capital Tunis January 14, 2011. [Photo/Agencies]

TUNIS, Tunisia - Violent anti-government protests drove Tunisian President Zine El Abidine Ben Ali from power Friday after 23 years of iron-fisted rule, as anger over soaring unemployment and corruption spilled into the streets.

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 and unconfirmed news reports citing unidentified government sources said Ben Ali had left the country.

Tunisia's President Zine al-Abidine Ben Ali waves to supporters after he took the oath at the national assembly in Tunis in this November 12, 2009 file photo. [Photo/Agencies]

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."