Egyptian security forces Saturday cleared central Cairo's Tahrir Square and the roads leading to the US embassy, after clashes with protesters claimed the lives of two demonstrators, DPA reported.
Protesters were rallying against a US-made film that mocks Islam's prophet Mohammed.
The move came after several days of fighting between police and protesters using stones and tear gas, witnesses said.
"Security forces cleared the area after several initiatives to end the clashes have failed, and since all political and revolutionary groups have condemned the violence," Interior Minister Ahmed Gamal Eddin said while visited the area on Saturday after calm was restored.
More than 250 people were injured and two people died in hospital from injuries sustained during the clashes, the fiercest since the Muslim Brotherhood's Mohammed Morsi became Egypt's first Islamist president in June.
Prosecutors ordered the detention of 54 people for four days pending investigation. They face charges of intimidating people, resisting authorities, destruction of public and private property as well as possession of tools used to attack people.
On Tuesday, protesters scaled the walls of the US embassy, taking down the US flag and replacing it briefly with a black Islamist one. Since then, hundreds of protesters gathered in the area have clashed with police.
Meanwhile, a rights group said that the family of a Christian man - detained on charges of disseminating the anti-Islam video, which created massive unrest among Muslims worldwide - were being threatened.
The family of Alber Saber were forced to leave their home after they received threats saying their house would be burnt down, the Cairo-based Association for Freedom of Thought and Expression said.
An angry crowd surrounded Saber's house of Thursday after he posted a video of the film on his Facebook page. When his family called police for protection, security arrested Saber on charges of blasphemy.
The film, Innocence of Muslims, which portrays the prophet as a womanizer and a paedophile, has sparked angry protests in several Muslim countries.
Insurgents killed Tuesday the US ambassador and three other Americans in Libya. Protesters also attacked the US embassies in Yemen, Tunisia and Sudan.
Tahrir was the rallying point of massive protests that eventually forced Hosny Mubarak to step down in February last year.