US President Barack Obama has said the transition of power in Egypt must begin now, but details of the process have to be worked out by Egyptians.

He was speaking as tens of thousands of people continue to protest in the capital Cairo, calling on Egyptian President Hosni Mubarak to resign.

Mr Obama urged Mr Mubarak to heed the call of the Egyptian people for an orderly transition of power, saying the country could not go back to the ‘old ways’.

‘He needs to listen to what is voiced by the people and make a judgment about a pathway forward that is orderly, that is meaningful and serious,’ Obama said, in carefully worded comments on Egypt's political future.

‘I believe that President Mubarak cares about his country. He is proud, but he is also a patriot,’ Mr Obama said, in comments which appeared to deliver a broad hint that Mr Mubarak should go sooner rather than later.

Cairo's Tahrir Square was teeming with people chanting ‘Leave, leave, leave!’, waving Egyptian flags and singing the national anthem, with a beefed-up military presence keeping pro-Mubarak activists away to prevent any bloodshed.

Friday prayers were held on the square in an 11th day of unprecedented mass rallies to try to topple Mubarak. One cleric praised the ‘revolution of the young’ and declared: ‘We want the head of the regime removed.’

‘Game over’ said one banner, in English for the benefit of international television channels beaming out live coverage. Effigies of Mubarak hanging by the neck dangled over the square.

Turnout nationwide seemed short of the more than one million seen on Tuesday and which leaders had hoped to match on what they called ‘Departure Day’, a week after last Friday's ‘Day of Wrath’ to voice rage over poverty, repression and corruption.

Some Egyptians, weary of disorder, feel Mr Mubarak did enough this week by pledging to step down in September and were wary of more violence by Mubarak loyalists, but others were resolute he had to quit to usher in a new chapter of modern Egyptian history.

Despite mass street protests and concessions by government, Mr Mubarak's fate now lies as much in deals struck among generals keen to retain influence and Western officials anxious not to see a key ally slide into chaos or be taken over by Islamists.

The role of the army, revered in Egypt compared to police and other security apparatus which are feared, is vital in determining the future of the Arab world's most populous nation.

European Union leaders echoed calls from the United States for Mubarak to do more than promise not to run in September's election: ‘This transition process must start now,’ they said.

The 82-year-old president said yesterday he was ‘fed up’ but would not stand down as that would create chaos in Egypt.

In his first interview since the protests erupted, Mr Mubarak blamed the Muslim Brotherhood for the violence of recent days, ABC television's Christiane Amanpour reported.

The veteran leader was ‘fed up with being president and would like to leave office now, but cannot, he says, for fear that the country would sink into chaos,’ Amanpour said.

‘He told me that he is troubled by the violence we have seen in Tahrir Square over the last few days but that his government is not responsible for it. Instead, he blamed the Muslim Brotherhood.’

Mr Mubarak's onetime foreign minister, Arab League chief Amr Mussa, said he doubted his former boss would leave any time soon.

‘I do not think he will leave. I think he will stay until the end of August,’ Mr Mussa told France's Europe 1 radio before himself later venturing out into Tahrir Square in what his office described as a ‘calming gesture.’

There were also demonstrations for Mr Mubarak's departure in a raft of provincial cities.

In Egypt's second city Alexandria, tens of thousands gathered in the city centre and Brotherhood official Sobhi Saleh said tens of thousands more were marching in from various suburbs.

In Luxor in the south and Mansura and Mahalla in the Nile Delta, tens of thousands demonstrated, a security official said. There were smaller protests in the cities of Assiut, Menufiya and Suez, he added.

West critical of Mubarak supporters

Western governments have been increasingly strident in their criticism of the deadly violence unleashed by Mubarak supporters.

State Department spokesman Philip Crowley said Washington had traced the violence to ‘elements close to the government and the ruling party’ even if it is not clear how far ‘up the chain’ it goes.

Washington has been pushing proposals for Vice President Omar Suleiman, Mr Mubarak's veteran intelligence chief to head a transitional government, which would immediately begin a process of constitutional reform aimed at paving the way for free and fair elections in September, the New York Times reported.

‘Senior administration officials said that the proposal was one of several options under discussion with high-level Egyptian officials around Mr Mubarak in an effort to persuade the president to step down now,’ the paper said.

UN chief Ban Ki-moon said after talks in Berlin that the transition process should start ‘as soon as possible ... the sooner the better.’

British Prime Minister David Cameron said: ‘Frankly the steps taken so far haven't met the aspirations of the Egyptian people.’

But Italian Prime Minister Silvio Berlusconi urged caution in handling the transition in a country long been seen as a pivotal Western ally in the volatile Middle East.

‘We are hoping for a transition in Egypt that brings more democracy without breaking with a president like Mubarak that the West, and first and foremost the United States, consider as wise, a reference for the entire Middle East,’ he said.

Iran's Khamenei weighed in, deriding Mubarak as a ‘servant’ of Israel and urging the Egyptian people to establish an Islamic republic.

‘Do not back down until the implementation of a popular regime based on religion,’ she said in his sermon at the main weekly Muslim prayers in Tehran, switching from Persian to Arabic for the benefit of his Egyptian target audience.