An Egyptian policeman was killed by a roadside explosive near the Cairo suburb of Maadi on Sunday, the Egyptian Interior Ministry said in a statement, state-run Ahram Online website reported.
An improvised explosive device planted on the roadside went off shortly after midnight as a military vehicle passed by, killing one police officer and injuring four others, according to the statement.
An initial examination suggested the bomb was detonated remotely by a mobile phone SIM card, a senior Interior Ministry official told state news agency MENA.
A joint task force made up of several police units is questioning tenants of the flats overlooking the site of the attack to try to identify and arrest the culprits, the official said.
There was no immediate claim of responsibility by any group.
Egypt has been fighting a wave of anti-security attacks following the ouster of former Islamist leader Mohamed Morsi in 2013.
Those attacks, which were mainly centered in Sinai while rarely happened in Cairo, have killed hundreds of soldiers and policemen.
A local affiliate of the Islamic State group in North Sinai Province has claimed responsibility for most of the attacks. Enditem