Four gunmen killed eight police officers dressed in plainclothes south of Cairo on Sunday, foreign media reports.
The officers were traveling in a government minivan and conducting security checks in Helwan district when they were attacked, the Egyptian Interior Ministry said in a statement.
The gunmen shot and killed all of the officers before escaping, the statement said.
ISIS claimed responsibility for the attack in a statement posted by a supporter of the terror group.
It described the attackers as a "security unit of the caliphate soldiers" and said they have safely returned to their positions.
Egyptian security forces have been deployed to the district, setting up checkpoints and launching an intensive search to find those responsible.
Based on the number of bullet casings found on the scene, authorities believe the attackers used automatic weapons.