A third bomb has gone off in Cairo near police headquarters after a car bomb and metro station bomb exploded.
The third bomb comes after the second bomb near a metro station wounded five police, hours after a car bomb struck police headquarters in the Egyptian capital, killing four people, the health ministry said.
State television had earlier reported that one person was killed and 15 wounded in the second bombing, but a health ministry official told AFP there had been no deaths.
He said the makeshift bomb had been planted near the entrance to the metro station
Dozens of people are feared injured after the first bomb blast, which left a huge crater in the ground.
The attack came a day before police were to deploy across the capital for the third anniversary of the 2011 uprising against Hosni Mubarak, with Islamists calling for mass protests against the new regime.
It was not immediately clear how the car bomb was brought so close to the police headquarters, which is surrounded by a high metal fence that was partially destroyed in the blast.
The explosion left a large crater at the gate, and badly damaged the building’s facade as well as that of a nearby Islamic museum.
Riot police pushed back hundreds of onlookers, some of whom chanted slogans against the Muslim Brotherhood.
“It was a car bomb,” interior ministry spokesman Hany Abdel Latif told AFP.
Egyptian state TV reported that casualties were being rushed to Ahmed Maher & Gomhuria hospitals as security forces converged on the area.
A large number of ambulances were on hand.
There were also reports of gunfire in the area immediately after the blast.
The trouble-torn nation has been in the grip of civil unrest for almost six months since the government of Mohammed Morsi was overthrown and a military-backed interim government installed.
Millions protested against the rule of Morsi and the Brotherhood over the summer, prompting the coup.
Since then, pro-military media have touted the police as heroes and often brand secular activists critical of the police, military or Mansour’s government as either Morsi’s supporters or foreign agents.
The government has been increasingly criticised for its harsh crackdown on any dissent.
Since President Morsi’s ouster on July 3, security forces have jailed thousands of members of his Muslim Brotherhood, which has also been declared a terrorist organisation.