A homemade bomb exploded in central Cairo on Tuesday, security officials said.
The target of the blast, near a busy square, was not immediately clear. There was no immediate word on casualties.
Islamist militants seeking to topple the government have carried out numerous bombing attacks on soldiers and police since the army toppled President Mohamed Mursi of the Muslim Brotherhood in 2013.
Last week, Islamic State’s Egyptian affiliate staged coordinated attacks in the Sinai Peninsula which killed more than 30 security personnel.