Three bomb explosions hours apart in Egypt's capital have killed at least five people and wounded dozens.
The bombings came on the eve of the anniversary of the start of the 2011 uprising that toppled Egypt's ruler Hosni Mubarak.
A suicide car bomber targeted Cairo's police headquarters, which killed four people and badly damaged a nearby Islamic museum.
It is unclear how the bomb was brought so close to the police headquarters, which is surrounded by a high metal fence.
State television quoted witnesses as saying gunmen on motorcycles opened fire on buildings after the explosion.
It was followed by two more smaller explosions within hours - one at a metro station in Giza which killed one person, and another at a police station near the pyramids.
Reporter Tom Rayner said the explosion by the pyramids was possibly caused by a grenade.
Militants have escalated attacks since the military overthrow of Islamist president Mohamed Morsi in July.
Morsi's Muslim Brotherhood has denied involvement in the attacks, but was blacklisted as a terrorist group after 15 people were killed when a suicide bomber blew up a vehicle at a police headquarters north of Cairo in December.
