Three persons were shot dead at the 20-house unit area in Wellampitiya.
Three residents of the same area aged 19, 24 and 49 were killed in this shooting that took place at 11.55 last night.
The Welllampitiya police said that the three persons killed were relatives.
Similarly a gang that came in a vehicle had fled after carrying out the shooting while the victims were staying in a house at the 20-house unit area.
The victims who were in serious condition succumbed to injuries after being admitted to the Colombo National Hospital.
The magistrate investigation and post mortem on the deceased persons are scheduled to be held today.
The reason for the shooting has so far not come to light.