The gunmen travelling in a truck stopped a microbus carrying the policemen in Omar Ibn Abdel Aziz street and sprayed it with bullets before fleeing from the scene, a security source said.
Four armed terrorists got out of the truck and opened fire on the police microbus, according to a statement by the Ministry of Interior.
Security forces have rushed to the place of the incident and are currently searching for the attackers, it said.
Islamist group Shabab el-Mokawma el-Shabia (public resistance) has claimed responsibility for the attack.
The attack came to commemorate 1000 days of the attack, it said.
Egypt has witnessed several violent attacks by militants since the January 2011 revolution that toppled former president Hosni Mubarak.
Terrorists, including from dreaded Islamist State outfit, have killed hundreds of policemen and soldiers in attacks conducted mostly in the Sinai Peninsula and in and around Cairo.
The attacks targeting police and military increased after the ouster of Islamist ex-president Mohamed Morsi in 2013 by military following massive protests against his rule.
