Mr Mubarak stepped down as leader on Friday, after 18 days of widespread anti-government demonstrations.

The country is now in the hands of the high command of the armed forces, headed by the defence minister.

US President Barack Obama called Egypt an inspiration, but said it must now move to civilian and democratic rule.

Demonstrators in central Cairo continued to celebrate the departure of Mr Mubarak into the night, dancing, chanting slogans and singing songs.

While many continue to enjoy the moment, many other Egyptians are already returning to work.

Outside state TV and other government buildings, the army and their tanks are still out in force.

So far the military have given few details of how they are going to run the country.

It's even not clear if the vice-president or any of Mr Mubarak's officials still retain their posts.

The army have given the impression of being above politics - a unifying force for the nation. But the opposition will want an early and clear indication that this country is headed in a new direction, and not simply swapping one dictatorship for another.

In Cairo's Tahrir Square - the heart of the demonstrations - the news was greeted with jubilation by a crowd of tens of thousands.

A huge poster hanging in the square read, "Breaking news: The people have brought down the regime."

Mr Mubarak has already left Cairo and is in the Red Sea resort of Sharm el-Sheikh where he has a residence, officials say.

The anti-government protests that began on 25 January were triggered by widespread unrest in Egypt over unemployment, poverty and corruption.

The BBC's Jon Leyne in Cairo said the announcement caught everyone by surprise: all over the city, drivers honked their horns and people fired guns into the air.

"Egypt is free," Mahmoud Elhetta, a protester, shouted.

"We are a great people and we did something great. This is the expected end for every dictator."

In the southern city of Assiut, people fired guns in the air and roamed the streets on motorcycles or pick-up trucks, while coffee houses handed out free drinks.

Egypt's state television, a bastion of support for Mr Mubarak's government, started reporting the celebrations across the country.

Opposition leader Mohamed ElBaradei described it as "the greatest day of my life."

Announcing Mr Mubarak's resignation on Friday, Vice-President Omar Suleiman said the president had handed power to the army.

Mr Suleiman said on state TV that the high command of the armed forces had taken over, a body composed of high-ranking generals and headed by Defence Minister Mohamed Hussein Tantawi.

"During these very difficult circumstances Egypt is going through, President Hosni Mubarak has decided to step down from the office of president of the republic and has charged the high council of the armed forces to administer the affairs of the country," he said.

"May God help everybody."

After Mubarak's resignation, a military spokesman appeared on state TV and promised the army would not act as a substitute to a "legitimate government acceptable to the people."

He said the military was preparing the next steps needed to achieve the ambitions of "our great nation" and would announce them soon.

US diplomatic cables published by Wikileaks described Field Marshal Tantawi as "aged and change-resistant", but committed to avoiding another war with Israel.