Cairo: Egyptian president Hosni Mubarak’s son, who is considered as his successor, has fled to Britain along with his family, the Times of India reported online quoting a US-based Arabic website.

The plane with Gamal Mubarak, his wife and daughter on board left for London Tuesday from an airport in western Cairo, the website Akhbar Al Arab said, according to the Times website.

The report came as Twitter confirmed late Tuesday that its website was blocked in Egypt, in an apparent move to thwart protesters using the social network in a campaign to oust Mubarak.

The US-based microblogging service that allows people to use mobile phones and computers to broadcast short text messages was out of service in Egypt, according to the herdict.org tracking website.

Twitter said in a terse "tweet" that it was blocked in Egypt starting about 1600 GMT and that the interruption had derailed Twitter.com as well as applications linked to the service there. "We believe that the open exchange of information and views benefits societies and helps governments connect with their people," Twitter representatives said in follow-up message.

Herdict.org, a project of the Berkman Center for Internet & Society at Harvard University, said it had received a "handful of reports" from users across different Internet service providers in Egypt saying they had been unable to reach Twitter.

A Herdict.org spokeswoman said that Vodafone Egypt denied that they have blocked Twitter. "From what we've heard from contacts on the ground, Egyptians are still utilizing the Twitter service via SMS and third-party apps," she said.

An Egyptian opposition group meanwhile called for a second day of street protests on Wednesday, a day after thousands joined unprecedented nationwide rallies.

The pro-democracy youth group April 6 Movement, which had launched the call for Tuesday's protests, urged people to head to Cairo's main square, just hours after police during the night fired tear gas on thousands of protesters to disperse them.

"Everyone needs to head down to Tahrir Square to take over the square once again," the group said on its Facebook page - which along with Twitter had helped to organise Tuesday's protests.

In a separate statement, it urged Egyptians to carry on protesting.

"To continue what we started on January 25, we will take to the streets to demand the right to life, liberty, dignity and we call on everyone to take to the streets... and to keep going until the demands of the Egyptian people have been met," the group said.

Tuesday's demonstrations, dubbed "the day of anger" and inspired by the uprising in Tunisia, left two protesters and one policeman dead.

The protests were considered the largest and most significant since riots over bread subsidies shook the Arab world's most populous nation in 1977.

Despite some 20,000 to 30,000 police being deployed in central Cairo, thousands of demonstrators marched to Tahrir Square on Tuesday, where they chanted in unison: "The people want the ouster of the regime."

Despite the call for further protests, calm returned to the streets of Cairo at daybreak on Wednesday after a night and a day of unprecedented demonstrations.

Sporadic clashes took place into early Wednesday, but by the pre-dawn hours police were in control of the square, milling about, while street sweepers cleared away rocks and litter. "Down with Mubarak" was still scrawled on a wall. Police trucks were lined up along a side street.

Washington, a close ally and major donor, called for restraint. Secretary of State Hillary Clinton said Mubarak's government was stable and seeking ways to meet Egyptians' needs.

"The Egyptian government has an important opportunity to be responsive to the aspirations of the Egyptian people and pursue political, economic and social reforms that can improve their lives and help Egypt prosper," a White House statement said.

Events in the region were a reminder that "all people yearn for certain things", such as free speech, a say in government and the rule of law, the White House added.