Violent clashes mark protests against Mubarak’s rule

by Karim Faheem and Mona El-Naggar

CAIRO — Tens of thousands of people demanding an end to the nearly 30-year rule of President Hosni Mubarak filled the streets of several Egyptian cities on Tuesday, in an unusually large and sometimes violent burst of civil unrest that appeared to threaten the stability of one of the United States’ closest Arab allies.