Egypt's defence minister visited Tahrir Square along with top army officials as thousands of protesters gathered for a mass rally to demand the immediate ouster of President Hosni Mubarak, on the 'Friday of Departure'.

This was the first visit to the epicentre of protests that have convulsed Egypt by a senior minister since they erupted on January 25.

'We are not going to leave until our demands are fulfilled,' protesters chanted from a bank of speakers in the middle of the square as Tantawi spoke to the army at the square's northern entrance near the Egyptian Museum.

Thousands of Egyptian protesters were gathered in a central Cairo square for the big day. 'Today is the last day ... today is the last day!' protesters shouted as Arabic pop songs blared from a bank of speakers: 'For Egypt, today is a day a celebration!'

The army had surrounded the square with tanks and armoured vehicles and erected barbed wire barriers. At one entrance it was letting people in from only one small gap, creating a choke point as people queued to join the growing crowd.

'The army and people are united,' the protesters chanted after a protester announced over loudspeakers that the minister was in the square.

A witness said a crowd gathered around the minister, who was also promoted to deputy prime minister in a cabinet reshuffle announced in the wake of the protests.

'Tantawi is here in the square near the Egyptian Museum in Tahrir talking to the army. The atmosphere is pleasant,' one protester on the scene said.

Many of the crowd had kept vigil in Tahrir (Liberation) Square overnight, while others pitched tents or slept on the ground, defying calls from the army and the vice president they should go home because their demands had been heard.

The army on Friday morning began removing barricades the protesters had erected after supporters of the president launched a deadly assault on them two days ago that left at least 10 dead and more than 800 wounded.

Organisers called on people to march from wherever they were towards the square, the state television building and the parliament building -- all within a mile of one another.

Protesters were checking IDs and bags as anti-government demonstrators streamed into the square, which was filling up while the atmosphere stayed relaxed.

'I will not wash, and I will not take my medicine until he leaves. We need freedom, all freedoms,' said Abdel Halim Mohamed Ali, 62, a technical school teacher.

'Omar Suleiman is good as long as he leads a temporary government. We welcome anyone who leads a temporary government, even (Coptic Christian) Pope Shenouda,' remarked Ali, a supporter of the Muslim Brotherhood.

On Friday morning, organisers called on people to march from wherever they were towards the square, the state television building and the parliament building -- all within a mile of one another.

Mubarak supporters on the main highway from Alexandria blocked cars from entering Cairo to prevent anti-Mubarak protesters from joining the demonstrations, a witness said.

Witnesses in the square said that soon after daybreak six army trucks had pulled up and soldiers begun dismantling a barrier at the northern end, prompting fears of a repeat of Wednesday's attack by men throwing petrol bombs, wielding sticks and charging on camels and horses.

'Protesters ran to argue with the army, but an officer said 'we are on your side, but we have orders from above to clear all barricades',' said Omar el-Mahdi, 28, who was one of those who went to talk to the army. 'This will open the way for thugs to come in unhindered.'

Protesters had formed human chains to guard the square and were checking the bags and identification cards of people as they entered to keep out pro-Mubarak supporters.

Protesters said barbed wire had been put out at all 12 entrance points to the square. Protester Shaaban Mindawy, 24, said the army, working with police, had been trying to prevent people from entering the square since Thursday evening.

'The officers were very stubborn,' Mindawy said, having found a way in from a side street.

'The army was confiscating food and medical supplies that people were trying to bring inside. The officers were telling people that thugs may attack them and take their money.'-Reuters