Thousands of angry Egyptians defied a curfew on Saturday for the second day in a row and stayed on the streets to push their demand that President Hosni Mubarak resign.
The army had warned that anyone who remained on the streets after 4 p.m. (1400 GMT) would be in danger, but as the deadline passed, protests continued in central Cairo and the port city of Alexandria, witnesses said.
Soldiers took no immediate action. They seemed relaxed and some protesters chatted with troops mounted on armoured vehicles, the witnesses said.
The Egyptian army used tanks and fired shots in the air to force back hundreds of protesters who were attacking the entrance to a building related to the Central Bank in a suburb of Cairo on Saturday, a witness said.
The protesters, who were using wooden planks to try to break into the building, which prints paper money, fled after seeing the tanks approach and hearing the shots.
On the fifth day of unprecedented protests against Mubarak's 30-year-rule, the president ordered troops and tanks into Cairo and other cities overnight and imposed a curfew in a bid to quell unrest in which dozens of people were killed.
In an effort to appease the protesters, he dismissed his cabinet and said he would listen to demands for reform.
The protesters, many of them young urban poor or students, are enraged over endemic poverty, corruption and unemployment as well as the lack of democracy in the most populous Arab nation. They pledged to press on with protests until Mubarak quits.
The unrest, which follows the overthrow of Tunisian strongman Zine al-Abidine Ben Ali two weeks ago in a popular uprising, has sent shock waves through the Middle East, where other autocratic rulers may face similar challenges.
Several thousand people flocked to central Cairo's Tahrir Square on Saturday, waving Egyptian flags and pumping their arms in the air in unison. "The people demand the president be put on trial," they chanted.
Troops made no attempt to break up the demonstration and protesters encouraged them to support their cause.
One Middle East expert, Rosemary Hollis, of London's City University, told Reuters the army had to decide whether it stood with Mubarak or the people.
"It's one of those moments where as with the fall of communism in Eastern Europe they can come down to individual lieutenants and soldiers to decide whether they fire on the crowd or not."
Over 74 is killed
In Alexandria, police used teargas and live ammunition against demonstrators earlier on Saturday.
Al Jazeera TV reported police opened fire on protesters trying to storm the Interior Ministry in Cairo, killing three, but the report could not be confirmed.
According to a Reuters tally, at least 74 people have been killed during the week although there was no official figure. Medical sources said at least 1,030 people were injured in Cairo.
Government buildings, including the ruling party headquarters, still blazed on Saturday morning after being set alight by demonstrators who targeted symbols of Mubarak's rule
As well as Cairo and Alexandria, clashes have also occurred in Suez, site of the strategically important canal.
"We are not demanding a change of cabinet, we want them all to leave, Mubarak before anyone else," said Saad Mohammed, a 45-year-old welder in Tahrir Square.
Mubarak, a key U.S. ally, has held power since the 1981 assassination of President Anwar Sadat and his government still rules with emergency laws.
He promised to address Egyptians' grievances in a television address on Friday but made clear he intended to stay in power.
No clear leader or organisation
So far, the protest movement seems to have no clear leader or organisation even if Mubarak did wish to open a dialogue.
Prominent activist Mohamed ElBaradei, a Nobel Peace Laureate for his work with the U.N. nuclear agency, returned to Egypt from Europe to join the protests. But many Egyptians feel he has not spent enough time in the country.
In an interview with France 24 television, ElBaradei said Mubarak should step down and begin a transition of power.
"There is a consensus in Egypt in every part of society that this is a regime that is a dictatorship, that has failed to deliver on economic, social, and political fronts," he said. The Muslim Brotherhood, an Islamist opposition group, has also stayed in the background, although several of its senior officials have been rounded up. The government has accused it of planning to exploit the protests.
The deployment of army troops to back up the police showed that Mubarak still has the support of the military, the country's most powerful force. But any change of sentiment among the generals could seal his fate.
Protesters in Tahrir Square mocked Mubarak's sacking of his cabinet as an empty gesture.
Mahmoud Mohammed Imam, a 26-year-old taxi-driver, said: "All he said was empty promises and lies. He appointed a new government of thieves, one thief goes and one thief comes to loot the country."
"This is the revolution of the people who are hungry, this is the revolution of the people who have no money against those with a lot of money."
The final straw appeared to be the prospect of elections due to be held in September. Until now few had doubted that Mubarak would remain in control or bring in a successor in the shape of his 47-year-old son Gamal.
U.S. President Barack Obama said he had spoken to Mubarak shortly after his speech on Friday and urged him to make good on his promises of reform. U.S. officials made clear that $1.5 billion in aid was at stake.
The European Union and other foreign governments appealed to Mubarak to show restraint and listen to the demands of the people but stopped short of suggesting he should quit. Saudi Arabia's King Abdallah expressed his support for him.
Britain, Germany and other countries advised their nationals against travel to the main cities hit, a development that would harm Egypt's tourist industry, a mainstay of the economy.
Banks will be shut on Sunday as "a precaution", Central Bank Governor Hisham Ramez told Reuters.
The stock market, whose benchmark index tumbled 16 percent in two days, will also be closed on Sunday. The Egyptian pound fell to six-year lows.