The US Sunday stepped up efforts for a speedy transition of power in Egypt, where embattled President Hosni Mubarak's powerful son Gamal and top leaders of ruling party quit their posts, amid reports that key opposition group Muslim Brotherhood has entered talks with officials on ending the 13-day revolt against the regime.
Protesters braved heavy rains to stay overnight at the Tahrir (Liberation) Square, the hub of the unrelenting demonstrations against Mubarak's 30-year regime.
The scene in Tahrir area, which has become a "tent city" with tens of thousands of people demonstrating there almost everyday, was relatively calm shortly before dawn Sunday,
Al-Jazeera said.
In a bid to end the crisis, the outlawed opposition group Muslim Brotherhood said it was joining talks with new Vice President Omar Suleiman, it said.
The group had previously rejected any dialogue until 82-year-old Mubarak steps down.
Describing the announcement as "highly significant", the channel said the Muslim brotherhood is "interested in talking about the resignation" of Mubarak.
However, the protesters vowed not to back down on their demand for Mubarak's immediate ouster. "We have to be steady to topple the government," Ahmed Abdel Moneim, a 22-year-old
student who has been sleeping in the Square for days, was quoted as saying by the channel. "... If we have to spend our life (like this) to get rid of Mubarak, we will."
US President Barack Obama called several world leaders to discuss the current situation in Egypt, emphasising the need for immediate beginning of an "orderly peaceful transition".
Obama spoke to Crown Prince Mohammed bin Zayed of the UAE, British Prime Minister David Cameron and Chancellor Angela Merkel of Germany, the White House said.
"The President discussed his serious concern about the targeting of journalists and human rights groups, and reaffirmed that the government of Egypt has a responsibility
to protect the rights of its people and to release immediately those who have been unjustly detained," it said.
"The President emphasised the importance of an orderly, peaceful transition, beginning now, to a government that is responsive to the aspirations of the Egyptian people, including credible, inclusive negotiations between the
government and the opposition," it said.
Separately, US Vice President Joe Biden called his new Egyptian counterpart Omar Suleiman to stress the need for "immediate steps" which demonstrate the Egyptian government's commitment to reforms, the White House said.
In his second call to Suleiman this week, Biden asked his Egyptian counterpart about the progress in beginning credible, inclusive negotiations for Egypt's transition to a democratic government to address aspirations of the Egyptian people.
"He stressed the need for a concrete reform agenda, a clear timeline and immediate steps that demonstrate to the public and the opposition that the Egyptian government is committed to reform," the White House said.
During the telephonic conversation, Biden expressed concern about continued raids on civil society and called for immediate release of journalists, activists and human rights advocates who have been detained without cause, it said.
Biden's last call to Suleiman was on Thursday when he said that the Egyptian government is responsible for ensuring that peaceful demonstrations do not lead to violence.
The Obama administration has, meanwhile, distanced itself from the remarks of its special envoy Frank Wisner that Mubarak should stay in office to ensure smooth transition of power.
"The views he (Wisner) expressed are his own. He did not coordinate his comments with the US government," State Department spokesman P J Crowley said.
According to media reports, Wisner had said that "Mubarak must stay in office in order to steer those changes through...
This is an ideal moment for him to show the way forward".
Despite mounting domestic and global pressure, the Egyptian president has remained defiant, refusing to quit immediately.
Mubarak's son Gamal and top leaders of ruling party quit their posts last night, but their conciliatory gesture drew a blank.
The six-member steering committee of the ruling National Democratic Party (NDP), including secretary-general Safwat el-Sharif, stepped down in a move to calm down protests against Mubarak.
Hossam Badrawi, a prominent physician who is believed to have good relations with opposition figures, has been appointed as the NDP secretary general.
The 13-day unprecedented anti-regime protests in Egypt have claimed over 300 lives.