The apparent fall of Mr. Ben Ali, whose authoritarian government ruled for more than two decades, would mark the first time in recent memory that widespread demonstrations had overthrown an Arab leader.
The country, which is determinedly secular, is a close United States ally in the fight against terrorism. But on Friday, after reports that Mr. Ben Ali had fled, President Obama made strong statements in support of the protesters.
Some demonstrators also cited the evidence of cables from the United States Embassy in Tunisia that were released by the anti-secrecy group WikiLeaks providing vividly detailed accounts of the first family’s self-enrichment and opulent lifestyle.
Online activists have attacked and at least momentarily disabled several Tunisian government websites in the latest act of protest against the country's embattled leadership.
The loosely organised hacker group Anonymous claimed responsibility for the cyber attack, which it called "Operation Tunisia", an apparent arm of the group's broader effort – termed "Operation Payback" – aimed at taking retribution against governments and businesses viewed as hostile to the similarly amorphous document-leaking group WikiLeaks.