Five Egyptian ministers have tendered their resignations from Mohamed Morsi's cabinet, a senior official has said, as protests against the president's rule filled the streets of cities throughout the country.

Earlier on Monday, the state news agency, MENA, said the ministers were considering resigning in sympathy with the protesters who were calling for the resignation of Morsi.

Those who resigned were the tourism minister, Hisham Zaazou; communication and IT minister Atef Helmi; the minister for legal and parliamentary affairs, Hatem Bagato; water minister Abdel Qawy Khalifa; and environment minister Khaled Abdel-Aal.

They handed in their letters of resignation together to Prime Minister Hisham Qandil, the official said.

Al Jazeera's Hoda Abdel Hamim said the resignations were a "soft blow" for Morsi, as the ministers were not among his key Cabinet members. Tourism minister Zazou tried to resign last month after Morsi appointed Adel al-Khayat, a member of an Islamist party linked to a massacre of tourists in Luxor, as governor of the temple city. Khayat later quit.

The resignations came during a second day of demonstrations against Morsi, who completed one year in office on Sunday.

Brotherhood HQ burned

In the capital, Cairo, the official building of the powerful Muslim Brotherhood to which Morsi belongs, was set ablaze before people stormed and looted the building. The interior ministry said that eight people had been killed in the violence.

People were seen leaving with petrol bombs, helmets, flak jackets, furniture, televisions and documents.

Mohamed ElBeltagy, of the Brotherhood, told AlJazeera that he rejected a claim that his members opened fire from inside the headquarters at attackers.

Many anti-Morsi protesters spent the night in dozens of tents pitched at Cairo's central Tahrir Square and the palace, positions organisers say they will hold until Morsi resigns.

In fewer numbers, supporters of the Egyptian president came out on Sunday to show their support and defend the legitimacy of the president.

In total, 16 people have been killed and hundreds wounded in clashes between pro- and anti-Morsi groups.

The main opposition Tamarod - Arabic for rebellion - movement, which led the demonstrations, gave Morsi a deadline of Tuesday to quit, threatening a campaign of civil disobedience if he stays.

The number of people who joined in protests on Sunday was between 14m and 17m people, the interior ministry told Al Jazeera.

"It is absolutely fair to say that an unprecedented number of Egyptians went to the streets accross the country," said Al Jazeera's Hoda Abdel Hamid, reporting from Cairo.

She added that a statement from Morsi during the protests was not welcomed by many, as it did not offer anything new.

In the message released on Sunday, he said: "I believe we can come together and find a way that builds our country," and he could "engage in national dialogue."

In its statement, Tamarod urged "state institutions including the army, the police and the judiciary to clearly side with the popular will as represented by the crowds."

The group also rejected presidential calls for dialogue, saying: "There is no way to accept any halfway measures."

A few kilometres away from the presidential palace, thousands of Morsi supporters also staged their own sit-in to show support for their president.

Morsi announced to all of Egypt's people he made mistakes and that he is in the process of fixing these mistakes - Omar Amer, presidential spokesman ,

Presidential spokesman Omar Amer said Morsi was serious in his repeated calls for national dialogue.

"[Morsi] announced to all of Egypt's people he made mistakes and that he is in the process of fixing these mistakes," Amer told a late-night news conference.

The duelling rallies on Sunday only further highlighted the deepening political polarisation in Egypt.

Morsi supporters are full of praise for his first year in office, insisting that the president has strengthened civilian rule in Egypt and done his best to manage a failing economy.

Anti-government protesters' main complaint was the worsening economy, which has been in free-fall since Morsi took office, with the Egyptian pound losing nearly 20 percent of its value and industry crippled by fuel and electricity shortages.

"He's borrowed money from everyone in the world," said Said Ahmed, referring to $11bn in loans Egypt has received from Qatar, Saudi Arabia and Turkey to prop up the economy. "Who's going to pay for that? Our children."