The previous military-appointed civilian cabinet resigned this week after violent protests in Cairo and other cities.
Justifying the wall, the country's generals said they would not allow the Interior Ministry to be threatened.
The nation's leaders also said there would be no delay in the parliamentary elections due to start on Monday - despite nearly a week of continuous rioting which has claimed dozens of lives.
"The election will be held on time with all of its three stages on schedule," Major-General Mamdouh Shaheen said yesterday.
The apparent rejection of any transfer of power to a civilian council - two days after Field Marshal Hussein Tantawi said the military would consider a referendum on the matter - leaves unresolved one of the main sticking points of this crisis.
Major-General Mukhtar el-Mallah claimed relinquishing power would be a "betrayal of the trust placed in our hands by the people".
"We will not relinquish power because a slogan-chanting crowd said so," he added. "Being in power is not a blessing. It is a curse. It's a very heavy responsibility."
Ramy el-Swissy from the April 6 movement - an influential youth group that has demanded the introduction of an interim civilian government - said protesters would remain in Tahrir Square until the generals made further concessions. "We will make sure that we won't leave until our demands are met," he said.
Yesterday the ruined streets of central Cairo lay quiet for the first time since Saturday, after a truce brokered between protesters and the police. But the recent chain of violence has been the worst since Mubarak was toppled in February, claiming nearly 40 lives, according to human rights groups.
The military has offered an apology for the deaths of so many civilians. But yesterday Egypt's leading human rights organisations denounced the "fallacious statements" of the authorities and called for the resignation of senior officials, including the Interior Minister, General Mansour el-Essawi.
"Statements from the Interior Ministry included blatant lies denying that their forces fired live ammunition," said the NGOs in a joint statement, adding that the Military Council had supported the use of "brutal violence" against demonstrators.
Divisions have also emerged within the Muslim Brotherhood, whose political wing is expected to romp to victory in the elections.
Senior members of the organisation opposed any participation in the Tahrir Square sit-in, keen to avoid anything which could jeopardise their landmark bid for power.
But members of the Brotherhood Youth happily ignored their senior leaders, while other political parties accused the organisation of opportunism.
- Independent
