World leaders voiced mounting fears as thousands of protesters clashed with troops in Egypt, calling for restraint on all sides and urging Egyptian leaders to heed the cries for reform.
Leading a chorus of global concern, US President Barack Obama called on Egyptian President Hosni Mubarak to take concrete steps towards political reform, and to refrain from using violence against protesters.
"The people of Egypt have rights that are universal," Obama said shortly after speaking by telephone for 30 minutes with the Egyptian leader, whose country has been rocked by four days of protests against his rule.
Obama said he told Mubarak to deliver on promises made in a speech to the Egyptian people to introduce democratic and economic reforms.
"I told him he has a responsibility to give meaning to those words. To take concrete steps and actions that deliver on that promise," Obama said.
Some 27 people have been killed in the four days of countrywide anti-government rallies, which have also left more than hundreds injured and thousands in detention.
In a televised address early Saturday, Mubarak said he had sacked Egypt's government and vowed to bring in democratic and economic reforms.
"I have asked the government to resign and tomorrow there will be a new government," a stoney-faced Mubarak said. "We will not backtrack on reforms.
"We will continue with new steps which will ensure the independence of the judiciary and its rulings, and more freedom for citizens," he added.
Mubarak has played a key role as a powerful regional voice in the Israeli-Arab conflict during his 30 years in power.
And Washington, like many Western governments which have dealt with him, has struggled to formulate a response to the rapidly evolving crisis.
Earlier, US Secretary of State Hillary Clinton said the protests "underscore that there are deep grievances within Egyptian society and the Egyptian government needs to understand that violence will not make these grievances go away."
The crisis -- inspired by the events which led to the ouster of Tunisia's long-time ruler earlier this month -- is to be discussed at a meeting of EU foreign ministers in Brussels on Monday.
"The continued use of force against demonstrators by police and state security forces is deeply troubling," said Catherine Ashton, the European Union's top foreign policy official.
She also called on Egyptian authorities to release all those rounded up in a crackdown on the protests.
Demonstrations also flared in central Paris Friday, calling for Mubarak's ouster, as well as outside the Egyptian embassies in Montreal and Caracas.
British Prime Minister David Cameron added his voice to the calls for reform in Egypt, after his Foreign Secretary William Hague warned of a "great danger of violence" due to the huge numbers of people on the street.
"What we need is reform in Egypt," Cameron told CNN television. See pics
"I mean we support reform and progress in the greater strengthening of their democracy and civil rights and the rule of law. Clearly there are grievances that people have and they need to be met and matched." Blog
France also voiced concern. "Only dialogue among all the parties" can improve matters, said French Foreign Minister Michele Alliot-Marie, adding such talks must "take into account aspirations that are being expressed for more liberty and democracy.
Eyeing a tide of regional unrest, which also saw demonstrations erupt on the streets of Yemen on Thursday, UN chief Ban Ki-moon Ban appealed to Arab governments to take note.
"What I have been saying repeatedly is that first of all, all concerned people or leaders should ensure that the situation in that region, particularly now in Egypt, does not and should not lead to further violence," he said.
Swedish Foreign Minister Carl Bildt criticised the decision by Egyptian authorities to cut off Internet access, saying Myanmar was the only other country he could have think of to have taken the measure.
"In a situation like the one in Egypt, closing down the Internet may be downright dangerous," he warned. More pics
Halt crackdown on protestors, Obama tells Mubarak