Greek police returned fire after being shot at near a Roma camp located in a western Athenian suburb in the early hours of Thursday.
There were no injuries during the incident at Ano Liosia which occurred when the police called on the driver and three passengers of a suspicious vehicle to submit to an inspection near the camp.
According to reports, assailants opened fire from nearby rooftops to intimidate the officers who responded.
Several shots were fired by both sides. A police vehicle was damaged.
A manhunt to find the shooters is ongoing.