Protestors and police are clashing in Cairo despite the declaration of a state of emergency in three other major cities.
Police fired tear gas at stone-throwing youths early on January 28 near the capital's Tahrir Square.
One man was reportedly killed.
The clashes mark the fifth consecutive day of street violence in Egypt.
On January 27, Egypt's President Muhammad Morsi has declared a 30-day state of emergency in three cities and their surrounding provinces, where scores of people have been killed and injured in recent days in a wave of unrest.
The decree includes nighttime curfews in Port Said, Ismailia and Suez.
In his address, Morsi also pledged to launch a dialogue with “political figures” in a bid to resolve the latest crisis.
The recent days of unrest have left around 50 people dead, mostly in the Mediterranean coastal city of Port Said.
At least seven people were reported shot dead and more than 400 injured as unrest continued in the city on January 27
More than 30 people were reported killed in Port Said a day earlier after a court approved death sentences on football fans over deadly rioting in the city last year.
Army forces have been deployed in Port Said and Suez.
Further clashes between protesters and security forces were also reported on January 27 in Cairo’s Tahrir Square and in Egypt’s second city, Alexandria.
This latest round of bloodshed erupted as Egypt last week marked the second anniversary of the 2011 uprising that toppled longtime ruler Hosni Mubarak.
In his speech, President Morsi said he was imposing the state of emergency – which gives police sweeping powers of arrest – to crack down on what he described as “vandals and lawbreakers.”
He also offered a dialogue with political forces as a way to help the country out of what he called a “dire situation.”
A statement by Morsi’s office said the leaders of the National Salvation Front, the main opposition coalition, was among those invited to attend talks at the presidential palace on January 28.
A spokesman for opposition coalition blamed Morsi's controversial policies for contributing to the unrest.
National Salvation Front spokesman Khaled Dawoud, however, also told the Reuters news agency that the president should have acted far sooner to impose extra security measures to curb the violence, which he blamed on criminals and thugs.
Pro-reform protesters accuse Morsi of failing to fulfill the democratic goals of the revolution and of surrendering the nation’s development to the Muslim Brotherhood, the main political force behind the president.
Morsi, a former senior figure of the Muslim Brotherhood, was elected in a democratic poll at the end of June to become Egypt’s first Islamist-backed president.
Among other demands, protesters are seeking the cancellation or amendment of Egypt’s new constitution, which was passed in a controversial referendum in December.
The charter, drafted by a council dominated by Islamists, has been criticized for failing to guarantee basic democratic rights and freedoms for women and members of minority groups.
The unrest comes with many Egyptians frustrated over a continuing economic downturn. The turmoil of the past two years has led to a sharp decline in tourism and foreign business investment in Egypt.
Based on reporting from Reuters, AFP and AP