As the sun was setting, tens of thousands of protesters began marching in Tahrir Square, responding to an invitation for a million-man march that is planned to head towards the cabinet office.

Some of the protesters chanted slogans against the Ministry of Interior and the Supreme Council of the Armed Forces (SCAF).

Others called on Field Marshal, and de-facto president, Hussein Tantawi to step down.

Traffic in downtown Cairo has not been blocked so far despite the increasing number of demonstrators.

Mohamed Adel, spokesman of the April 6 Youth Movement, says there is no intention to block traffic or to call for civil disobedience.

On the other hand, Bothaina Kamel, TV presenter and the only female presidential candidate, took one of the podiums to say: “The Mogamma [the largest governmental administrative building in Egypt] will be opened on Wednesday and Thursday [as previously announced] in order for those who intend to go on pilgrimage or Umrah to be able to finish their paperwork."

Ahmed Ezzat, member of the Popular Committees for Defence of the Revolution, said: “After today’s protest we are planning to start other marches tomorrow from working class neighborhoods, including Imbaba.

“We are not worried over the possibility of losing public support; when we staged a sit-in in protest against the appointment of Ahmed Shafik as prime minister we were less than a thousand. But eventually we achieved what we were after and were praised by everyone.

“Now there are thousands in the current sit-in, which means we are on the right track.”

At around 6pm, around three thousand protesters marched from the square towards the Cabinet office to demonstrate their displeasure with the interim government's handling of the revolution's demnds.

The demonstrators mainly chanted varied slogans against the Supreme Council of the Armed Forces (SCAF) while marching. Other protesters remain in Tahrir Square to protect it from possible raids, while some organised a popular committee to protect the National Museum with others manning entrances in to the square

Some of the marchers, whose mood was quite upbeat, stood next to parked cars on El-Qasr El-Eini Street to protect the vehicles from any possible, and unintentional, damage.

Others formed a human shield around the parliamentary premises.

The street is overcrowded but there haven’t been any signs of hostility so far.

The military officer responsible for securing the Cabinet‘s headquarters ordered the Central Security Forces deployed in the area to keep out of the protesters’ way as the latter were chanting “peaceful, peaceful.”

The march on El-Qasr El-Eini Street was joined up by another one coming from Parliament Street. Seconds later, the protesters chanted “one hand.” Later a huge Egyptian flag was unfurled in Parliament Street with protesters chanting: "It's our army, [Field Marshal] Tantawy don't try to scare us," and "the people and the army are one hand."

As the protesters marched in El-Qasr El-Eini Street, other people greeted them from the balconies of buildings on both sides of the square. "We are either bring back their [the martyrs who were killed in the first days of the revolution] rights, or die like them," chanted the protesters.