Two people were shot dead and two others were injured by unknown gunmen in the district of Neos Kosmos, in Athens, on Monday evening.
According to initial information, the victims and the perpetrators had arranged a meeting in a grove behind the church of Agios Sostis.
Police officers who arrived at the scene found several shell cases, while witnesses said a car was seen speeding away after the incident.
There were no further details about the identities of the victims or the possible motives of the shoutout.
The two injured individuals, a man and a woman, were transferred to the nearest hospital.
Greek Police (ELAS) is searching for a grey Opel.