ALEXANDRIA, Apr 6 (Aswat Masriya) - Unidentified gunmen opened fire on a church in the coastal city of Alexandria late Sunday, injuring a policeman and two passersby, Alexandria's security director said.

Director Mohamed al-Sharqawy told Aswat Masriya that those injured were transferred to hospital for treatment.

The West Alexandria Prosecution began investigation into the shooting on Monday morning, reported state-run al-Ahram.

Sunday marked Palm Sunday, a Coptic feast which celebrates the entry of Jesus into Jerusalem. 

Militants have stepped up attacks targeting security forces in Egypt, particularly in the Sinai Peninsula, since the army's ouster of Islamist President Mohamed Mursi in July 2013, which followed mass protests against his rule.