One person died and three were seriously injured at a shootout at the Agios Sostis Square on Syngrou Avenue on Monday evening, police said.
Earlier reports had said the dead were three, and did not specify the number of the injured.
According to preliminary information, a car sped away from the scene after the shootout, and several shells have been found in the area.
A strong contingency of police are at the area of Neos Kosmos which borders the Nea Smyrni suburb. The square is between the historic church and an all-day/all-night cafe.