Security forces have closed Tahrir Square after three explosions struck near the Ittihadiya presidential palace.
Two policemen were killed by the explosions on Monday morning.
The first policeman, Colonel Ahmed El-Ashmawy, was killed while attempting to defuse the first device. The name and rank of the second policeman has not been disclosed.
Monday marks the first anniversary of mass protests on 30 June 2013 that demanded the ouster of Islamist president Mohamed Morsi.
The Ittihadiya presidential palace and Tahrir Square were the two main centres of the protests.
Militants have escalated attacks against security forces since Morsi's ouster. Over 500 security personnel have been killed.