CAIRO // In his first response to the unrest sweeping his nation, Egypt's president fired his cabinet on Saturday and promised reforms but refused to step down, setting the stage for perhaps even heavier street battles with protesters calling for an end to his nearly 30 years in power.
Four days of the largest anti-government protests in decades exploded into chaos hours earlier. Tens of thousands of Egyptians fed up with crushing poverty, unemployment and corruption poured out of mosques after Friday's noon prayers and battled police with stones and firebombs.
Sources said at least 50 people had been killed and over a thousand injured in clashes in Cairo, Suez and Alexandria. By nightfall, they had burnt down and looted the ruling party's headquarters along the banks of the Nile and set fire to many other buildings, roaming the streets of downtown Cairo in defiance of a night curfew enforced by the army.
President Hosni Mubarak, confronted with the most dire threat to his three decades of authoritarian rule, faced his nation in a televised address at midnight, making vague promises of social reform in what is likely to be interpreted as an attempt to cling to power rather than a genuine pledge solve Egypt's pressing problems.
He also defended his security forces and accused the protesters of plotting to destabilise Egypt and destroy the legitimacy of his regime, outraging those still in the streets well into the night.
A heavy police crackdown and other extreme measures by the government - including the shutting down of all internet and mobile phone services in Cairo and other areas - did not stop the surging crowds. Egypt's crackdown drew harsh criticism from the Obama administration and even a threat Friday to reduce a $1.5 billion foreign aid programme if Washington's most important Arab ally escalates the use of force.
Stepping up the pressure, President Barack Obama told a news conference he called Mr Mubarak immediately after his TV address and urged the Egyptian leader to take "concrete steps" to expand rights and refrain from violence against protesters.
"The United States will continue to stand up for the rights of the Egyptian people and work with their government in pursuit of a future that is more just, more free and more hopeful," Mr Obama said.
Throughout Friday, flames rose in cities across Egypt, including Alexandria, Suez, Assiut and Port Said, and security officials said there were protests in 11 of the country's 28 provinces.
Calling the anti-government protests "part of a bigger plot to shake the stability and destroy legitimacy" of Egypt's political system, a sombre-looking Mubarak said: "We aspire for more democracy, more effort to combat unemployment and poverty and combat corruption."
His promises fell short of the protesters' demands for him to step down.
"Out, out, out!" protesters chanted in violent, chaotic scenes of battles with riot police and the army - which was sent onto the streets for the first time Friday during the crisis.
Egypt's national airline halted flights for at least 12 hours and a Cairo Airport official said some international airlines had cancelled flights to the capital, at least overnight. There were long lines at many supermarkets and employees limited bread sales to 10 rolls per person.