Calm returned to the streets of Cairo on Wednesday after demonstrations demanding an end to President Hosni Mubarak's 30-year rule, as protest leaders asked followers to regroup for a second day of action.

Police fired teargas and water cannon in the early hours of Wednesday to disperse protesters who occupied the Egyptian capital's central Tahrir square into the night.

Streets were mostly back to normal by morning, with some shops shut but traffic flowing.

Two protesters and one policeman were killed in clashes and protests that erupted on Tuesday in several Egyptian cities, where demonstrators angry at poverty and repression have been inspired by this month's downfall of the leader of Tunisia.

Opposition group Sixth of April Youth movement called on its Facebook page for protests to continue on Wednesday and after tomorrow, until Mubarak's departure.

Security forces said protesters would not be permitted to reassemble. A Reuters witness saw at least 10 riot trucks leaving a Cairo army base in mid-morning.

Change must happen. It must, said a butcher in central Cairo who asked to be identified simply as an Egyptian. That's life -- the old go and the young come with new ideas.

Police took back control of Tahrir square by dawn after sporadic clashes through the night. Demonstrators had taken over major roads and blocked traffic across the capital.

Down, Down Hosni Mubarak, protesters chanted after fleeing from the square in the early morning hours. Some threw stones at police, who charged them with batons to prevent the protesters returning to the square after it was cleared by using teargas.

Bullies, fleeing protesters shouted. Others cried: You are not men. Police sprayed a water cannon on protesters and moved in rows into the square.

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.

Twitter, the Internet messaging service that has been one of the main methods used by demonstrators to organise, said it had been blocked in Egypt. In a message, the company wrote: We believe that the open exchange of info & views benefits societies & helps govts better connect w/ their people.

Demonstrators on Tuesday tore up pictures of the president and his son, Gamal, who many Egyptians say is being groomed for office. Both Gamal and his father deny any such plan.

As cleaners swept the last debris from central Cairo's streets, state newspaper Al-Masry al-Youm arrived at newsstands with a red, one-word headline: Warning.

The difference is great between freedom of expression and chaos, Safwat el-Sherif, the secretary general of the ruling National Democratic Party told state newspaper al-Akhbar.

'DAY OF WRATH'

Tomorrow, don't go to work. Don't go to college. We will all go down to the streets and stand hand in hand for you our Egypt. We will be millions, wrote one activist on Facebook.

A government source said ministers had been told to ensure staff returned to work on Wednesday and did not join protests.

Web activists, who called for Tuesday's Day of Wrath against poverty and repression, have become some of the most vociferous critics of Mubarak and his three decades in office.

Their complaints echo those of fellow Arabs in Tunisia: soaring food prices, a lack of jobs and authoritarian rule that usually crushes protests swiftly and with a heavy hand.

Tuesday's demonstrations brought many thousands onto the streets of Cairo and several other cities in a coordinated wave of anti-government protests not witnessed since Mubarak came to office in 1981 after Anwar Sadat was assassinated by Islamists.

The population is growing 2 percent a year and has a youth bulge, with some 60 percent under 30 years old, including 90 percent of jobless Egyptians. About 40 percent of citizens live on less than $2 a day and a third are illiterate.

Demands by the protesters were posted on Facebook and passed around Tahrir square on slips of paper before police moved in.

They included calling for Mubarak to step down, Prime Minister Ahmed Nazif to quit, parliament to be dissolved and the formation of a national government. A union activist repeated the demands to the crowd in the square by megaphone.

Protests on Tuesday also erupted in Alexandria, cities across the Nile Delta and in Suez and Ismailia, east of Cairo.

Two protesters in Suez were killed by rubber bullets, security and medical sources said. State media said 102 members of the security forces were injured and one policeman died in Cairo because of a blow to the head from a stone that was thrown. Lawyers said dozens of demonstrators were detained.

The ministry blamed the Muslim Brotherhood for rioting that took place, although the banned Islamist group has only played a small part in protests. The group has even drawn the anger of its own youth members who say they have not been proactive enough.

Analysts say protests in Tunisia and developments across the region have made the claims of many Arab autocrats that they stand as bulwarks against Islamist radicals sweeping to power seem hollow.