Thousands of anti-government protesters, some hurling rocks and climbing atop an armored police truck, clashed with riot police Tuesday in the center of Cairo in a Tunisia-inspired demonstration to demand the end of Hosni Mubarak's nearly 30 years in power.
Police responded with blasts from a water cannon and set upon crowds with batons and acrid clouds of tear gas to clear demonstrators crying out Down with Mubarak and demanding an end to the country's grinding poverty.
Tuesday's demonstration, the largest Egypt has seen for years, began peacefully, with police showing unusual restraint in what appeared to be a concerted government effort not to provoke a Tunisia-like mass revolt.
As the crowds in downtown Cairo's main Tahrir square continued to build, however, security personnel changed tactics and the protest turned violent.
Demonstrators attacked the police water canon truck, opening the driver's door and ordering the man out of the vehicle. Some hurled rocks and dragged metal barricades. Officers beat back protesters with batons as they tried to break cordons to join the main group of demonstrators downtown.
To the north, in the Mediterranean port city of Alexandria, thousands of protesters also marched in what was dubbed a Day of Rage against Mubarak and lack of political freedoms under his rule.
In another parallel with the Tunisia protests, the calls for rallies went out on Facebook and Twitter, with 90,000 saying they would attend.
The protests coincided with a national holiday honoring Egypt's much-feared police.
Demonstrators in Cairo sang the national anthem and carried banners denouncing Mubarak and the widespread fraud that plagues the country's elections. The organizers said the protests were a day of revolution against torture, poverty, corruption and unemployment.
Mothers carrying babies marched and chanted, Revolution until Victory! while young men parked their cars on the main street and waved signs reading 'OUT!' inspired by the Tunisian protestations of 'DEGAGE!' this week. Men were seen spraying graffiti reading Down with Hosni Mubarak.
We want to see change just like in Tunisia, said Lamia Rayan, 24, one of the protesters.
The noisy crowd was joined by cars driving alongside and honking their horns.
People cried Long Live a Free Tunisia and waving Tunisian and Egyptian flags while police initially stood on the crowd's periphery.
The rallies came against a backdrop of growing anger in Egypt over widespread poverty and unemployment, as well as questions about whether Mubarak will run again in presidential elections later this year or perhaps position his son to run.
The first ramifications of the Tunisia uprising surfaced last week in Egypt when several people set themselves on fire or attempted to do so outside parliament and the prime minister's office.
Their actions sought to copy a young Tunisian vegetable vendor whose self-immolation helped spark the protests that forced Tunisia's authoritarian president to flee the country.
Nearly half of Egypt's 80 million people live under or just above the poverty line set by the United Nations at $2 a day. Poor quality education, health care and high unemployment have left large numbers of Egyptians deprived of basic needs.
The government has played down self-immolation attempts, with Prime Minister Ahmed Nazif telling reporters on Monday that those who committed the act were driven by personal issues.
Soon after the Jan. 14 ouster of Tunisia's longtime President Zine El Abidine Ben Ali, all eyes focused on Egypt, with observers wondering if the dramatic events in the North African nation could spur unrest against another entrenched Arab regime.
The call for protests was first initiated by The Martyr Facebook page, set up in the name of a young Egyptian man, Khaled Said, whose family and witnesses say was beaten to death by a pair of policemen in the Mediterranean port city of Alexandria last year. His case has become a rallying point for the opposition. Two policemen are currently on trial in connection with his death.