Tens of thousands of protesters have tried to force their way into Egypt's presidential palace, demanding withdrawal of the draft constitution and controversial decree which gives President Mohammed Mursi sweeping powers.
The angry anti-Mursi demonstrators forced the Islamist president to flee the palace, according to an unnamed presidential source quoted by Reuters.
It is thought that 100,000 Egyptians massed outside the palace in a collective outpouring of anger against the ruling Muslim Brotherhood and Mursi. Meanwhile thousands of people demonstrated in Cairo's historic Tahrir Square, and protesters even gathered outside Mursi's house in the capital's suburbs.
The activists were seen holding placards reading 'no to the constitution'.
According to the official Mena news agency, 18 people have been injured in the clashes. However, none of the injuries were critical.
"I know he's an elected president, but I think he lost his legitimacy. There are various articles in the constitution that violate the values of the Egyptian revolution, especially articles allowing civilians to be put on trial in military courts," protester Amany Moussa told Egypt's Ahram Online.
Scores of protesters remained in the capital through the night on Tuesday after opposition groups announced a sit-in outside the palace.
Although the police forces initially fired tear gas at the angry crowds, the security forces quickly pulled back to avoid an escalation of the violence. A police spokesperson later appealed for calm through a television address.
Nearly a dozen newspapers went on strike on Tuesday while the television channels in the country are planning to go blank on 5 December.
The anti-Mursi protests were sparked by the president's declaration of sweeping new powers, and exacerbated by the hastily drafted constitution by the Islamist-led assembly.