Crowds in Cairo swell ahead of “march of a million” (VIDEO)

Thousands of people are gathering in central Cairo, answering a call by opponents of President Hosni Mubarak for a "march of a million" Tuesday in the capital.

Many protesters defied a curfew to bunker down overnight in Tahrir Square, epicenter of the protests that have forced Mubarak to announce political and economic reforms, dismissed as inadequate by opposition figures.

Helicopters thundered low over central Tahrir Square early Tuesday, and tanks and police vehicles remained stationed throughout Cairo, but were reportedly not interfering with those gathering for the rally.

The military — which put Mubarak into power in 1981 — announced earlier it that it recognized the "legitimate demands" of the Egyptian people, and pledged not to fire on protesters.

Al Arabiya reported that authorities have blocked the road between the city of Suez and Cairo to stymie the flow of protesters.

Egyptian authorities shut down internet traffic and mobile phone service ahead of the protest, in the apparent hope that it would prevent demonstrators from coming to the square.

A second massive protest is planned Tuesday in the northern port city of Alexandria, but national train services were canceled for a second day, continuing what some consider an attempt by authorities to prevent rural residents from joining the urban protests.

Meanwhile, the Muslim Brotherhood, the Arab world's oldest and largest opposition movement, condemned the United Nations and Western countries for failing to take action against the government crackdown on protests and the killings of civilians.

At least 150 people have so far been killed and thousands more injured during clashes with government forces over the past week.

However, the Egyptian army's declaration that it would not use force against the protesters appears to have weakened Mubarak’s grip on power.

Mubarak late on Monday authorized his newly appointed Vice President Omar Suleiman to open a dialogue with the opposition.

"Today the president has instructed me to communicate with all political forces immediately in order to have a dialogue about all the disputed issues in relation to contituional and legislative reforms," Suleiman said at a press conference:

Suleiman, a longtime confidant of Mubarak, did not say what the changes will entail or which groups the government will contact.

A Western diplomat, who spoke to the New York Times on the condition of anonymity, said Suleiman's statement was believed to be part of choreographed maneuvers by the most senior people around Mubarak to set the stage for his eventual exit.

Crowds in the Egyptian capital have been growing with each day's protest since Saturday, when security forces stopped trying to halt demonstrators from gathering in the square.

The new arrivals on Tuesday seemed to energize protesters, who broke into a full-bodied roar of "Down, Mubarak, down!" according to the LA Times.

Mubarak would be the second Arab leader pushed from office recently by a popular uprising in the Middle East: Popular protests overthrew Tunisian President Zine el Abidine ben Ali on Jan. 14.

In Egypt, a nation of 80 million people — the region's most populous country and a Arab cultural center — protesters shrugged off years of heavy-handed state control and took to the streets on Jan. 25, in unprecedented revolt against Mubarak, his allies in the security forces and his National Democratic Party.

The protesters demand an end what they describe as a repressive, incompetent and corrupt regime that has failed to improve the lives of ordinary people while restricting civil liberties and violating human rights.

Though technically leaderless, they appear to have galvanized around Mohamed ElBaradei, a Nobel Peace Prize winner and former secretary general of the International Atomic Energy Agency.