Five people have been killed and about 90 wounded after three blasts in the Egyptian capital that appeared to target the police force.
The attacks began with a powerful car bomb that exploded outside the police headquarters in central Cairo, killing four people and wounding at least 76.
Within hours, two other blasts occurred elsewhere in the city, killing one person and injuring 15.
The attacks come on the eve of the third anniversary of the 2011 uprising.
The revolution forced the country's decades-long ruler Hosni Mubarak to resign.