Hundreds of thousands of pro-democracy protesters are expected to march on the streets of Cairo and other Egyptian cities on Friday, in what could become the largest - and some fear the most violent - protests thus far.

The demonstrators’ hopes for the resignation of the President were dashed on Thursday as Hosni Mubarak, in a 17-minute address on television, said he was determined to stay in power until September, when his current term ends.

Mubarak said he was handing "the functions of the president" to Vice-President Omar Suleiman and that he would oversee an "exit" from the current crisis, and "realise the demands voiced by the youth and citizens ... without undermining the constitution in a manner that ensures the stability of our society".

Before he finished his anticlimactic speech, protesters camped in Tahrir Square, the epicentre of Egypt’s revolution, shouted "donkey, leave!"

Rabab Al Mahdi, a professor at the American University in Cairo, told Al Jazeera that the level of anger and frustration at the square was "unprecedented".

"This is putting us into a messy situation that can turn bloody at any moment," she said, adding that the fact that Mubarak "for more than 10 minutes, was talking about himself - very narcissistic, again, giving the message that he's still in control, and this, in and by itself, offended people." 

Egyptian state television did not broadcast the scenes of anger after Mubarak's speech.

'People in tears'

Al Jazeera's Rawya Rageh, reporting from Cairo, said that halfway through Mubarak's speech, when the president spoke of his years in public service, people began taking off their shoes and waving them in the air in a dramatic Arab show of contempt.

"You could also see tears in some of the people's eyes ... a lot of screams of anger, people just breaking down in tears, people just breaking down in pain," our correspondent said.

Immediately after Mubarak's speech, Vice-President Suleiman called on the protesters to "go home" and asked Egyptians to "unite and look to the future."

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"Youth of Egypt, heroes of Egypt, go back to your homes and businesses. The country needs you so that we build, develop and create," Suleiman said.

"Do not listen to tendentious radios and satellite televisions which have no aim but ignite disorder, weaken Egypt and distort its image."

But the demonstrators were undeterred by his appeal and began to immediately mobilise for fresh protests on Friday in response to Mubarak's speech.

Protesters had previously planned "Friday of martyrs" to memorialise the 300 or more who have been killed during pro-democracy protests, which now have entered a third week.

More than 1,000 protesters moved overnight nearer to the presidential palace in the upscale neighbourhood of Heliopolis in central Cairo but only a few of them were still there on Friday morning.

In addition to occupying Tahrir Square, pro-democracy protests blocked access to the parliament building near the square.

Thousands of protesters were also surrounding the radio and television building in Cairo, which they see as a mouthpiece for Mubarak's regime.

"This marks a new front in our struggle against this illegitimate regime," wrote one protesters on the microblogging site Twitter. "Now that Mubarak has refused to quit, gracefully, he'll pay the price."

Workers on strike

Union workers have joined the protests over the past few days, effectively crippling transportation and several industries, and dealing a sharper blow to Mubarak’s embattled regime. Outraged by Mubarak’s defiance, many more workers vowed to join the planned protests on Friday.

The people's anger was not restricted to Cairo. In Alexandria, Egypt's second largest city, crowds began roaring and shouting and headed toward the military base of the northern command.

Al Jazeera's Jamal Elshayyal, reporting from that city, said pro-democracy protesters were "more offended than ever" at hearing that Mubarak's intention to remain in power until September.

"They really do not understand how President Mubarak cannot comprehend the strong sentiments which they have been expressing over the past two weeks," he said.

The US and EU said the announcement to transfer some powers to the vice-president was grossly insufficient and falls short of genuine reforms demanded by the people.

"The Egyptian people have been told that there was a transition of authority, but it is not yet clear that this transition is immediate, meaningful or sufficient," Barack Obama, the US president, said in a statement. 

Mohamed ElBaradei, a leading opposition figure, said Egypt "will explode" as a result of Mubarak's defiance and called on the Egyptian army to intervene "to save the country."