Protests in Egypt marking the second anniversary of the fall of President Hosni Mubarak have turned deadly.
Four people in the city of Suez were killed by gunfire on Friday. Another person is reportedly in a critical condition.
State TV showed protesters in Suez throwing stones at public buildings.
Officials say at least 186 civilians and 45 security personnel have been injured in clashes between protesters and police across the country.
Police clashed with opponents of President Mohammed Mursi as they converged on Tahrir Square in Cairo. There were also clashes in Alexandria.
Critics accuse the Muslim Brotherhood and President Mohammed Mursi of betraying the revolution. He denies this and has appealed for calm.
An appeals court recently overturned a life sentence imposed on Mr Mubarak, 84, over the deaths of protesters and ordered a retrial. He remains in detention at a military hospital.
The BBC reports checkpoints were earlier by protesters at the entrances to Tahrir Square to verify the identities of people passing through. Others set up an exhibition of photographs of those killed at various protests over the past two years.
Roads leading from Tahrir Square to several nearby government buildings and foreign embassies have been blocked by concrete walls since last November.
Demonstrators tried to dismantle one of them on Thursday night, but a new wall was built to block entry to the Cabinet headquarters.
The government is also blamed for a deepening economic crisis.
The president has dismissed the opposition's claims as unfair and called for a national dialogue.
Mr Mursi and his supporters accuse their opponents of undermining democracy by failing to respect their victory in elections a year ago.
In a speech on Thursday marking the Prophet Muhammad's birthday, President Mursi called on Egyptians to celebrate the anniversary "in a civilised, peaceful way that safeguards our nation, our institutions, our lives".