Cairo - The Egyptian army has asked President Mohamed Morsi to resolve huge protests against his rule or face intervention within 48 hours, placing huge pressure on country's first democratically elected leader.

In a statement on Monday, the army called on all groups – opposition and pro-Morsi alike – to resolve the situation. "The armed forces repeat their call for the people's demands to be met and give everyone 48 hours as a last chance.

"The national security of the state is in severe danger", it said, adding that if there was no resolution the army, "will be obliged by its patriotic and historic responsibilities ... to announce a road map for the future and the steps for overseeing its implementation, with participation of all patriotic and sincere parties and movements."

It described the mass protests on Sunday that brought out millions of Egyptians demanding President Morsi's resignation as "glorious".

It said protesters expressed their opinion "in peaceful and civilised manner", and that "it is necessary that the people get a reply ... to their calls".

Hours later, the army insisted in a second statement that it was not carrying out a coup, and said that it would not be part of the government. 'Huge pressure' Al Jazeera's chief political analyst Marwan Bishara said the statement undermined the authority of Morsi. "For the army to give the president 48 hours warning, the army are saying who is the boss," he said. "Morsi is no longer the same president as this morning in the eyes of those on the streets." He said the statement placed "huge pressure" on the president to resolve the protests, "otherwise we can expect army intervention". "That could be taking over the streets or taking over the government. This message is to the president. This undercuts his authority." Morsi was later photographed at the presidential palace in Cairo meeting the prime minister, Hisham Qandil, and defence minister Abdel Fattah al-Sisi.

Hours after the army's statement, helicopters flew over Cairo's Tahrir Square, the cradle of the 2011 revolution, trailing Egyptian flags to cheers of the crowd below. A loudspeaker blared: "The army and the people are one hand".

Tamarod, the main opposition group that has organised the protests, said the army statement showed it was taking the people's side. It urged its supporters to stay on the streets and squares of Egypt until Morsi's rule was ended.

The presidency cancelled a news conference due to take place late on Monday, while there was no statement forthcoming from the Muslim Brotherhood.

The army statment came hours after five of Morsi's ministers resigned. They 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.

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.

Brotherhood HQ burned

Egypt's street have been filled with pro and anti-Morsi protests since Sunday. 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.

Tamarod - Arabic for rebellion - 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.