Protesters threw Molotov cocktails at the building on Wednesday, setting parts of it on fire and also lobbed firebombs at the headquarters of the ruling National Democratic Party.
Thousands of Egyptians poured to streets across the country to continue the unprecedented demonstrations, defying a government ban announced earlier by the Interior Ministry.
Protesters burned tires and threw stones at police in Cairo while heavily armed riot police have been deployed in major cities to disperse crowds fed up with Mubarak's three-decade rule.
Clashes have been reported in Alexandria and the city of Suez, with security forces using water cannons, batons, rubber bullets and tear gas to break up the crowds.
At least 70 people -- 55 protesters and 15 police -- have been injured in the clashes in Suez, medics said.
Security officials say around 700 people have been arrested so far and at least four people, including a police officer, have been killed in two days of violent protests.
Reports say that Mubarak's son, Jamal Mubarak, who is considered his successor, fled to Britain along with his family on Tuesday.
Meanwhile, protest organizers have announced a general strike across the country.
According to the official website of the country's main opposition, Muslim Brotherhood, the general strike will be in place on Wednesday and Thursday.
A former Arab League envoy to the United Nations says the Tunisian revolution is inspiring the Arab world, which is worn-out by various dictatorial regimes.
In an interview, Clovis Maksoud said Tunisia's revolution "is one of the most inspiring events of the Arab world in the contemporary time."
The revolution "is the prognosis by which many frustrated people in various countries -- suffering dictatorship, poverty, and marginalization, are now being empowered," said the former ambassador to the United Nations.
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