The Mirihana police special investigations unit has arrested five suspects in connection with an attack on a group of Police Narcotics Bureau officers in Piliyandala recently.
Under interrogation one of the suspects had said that PNB officers were a real menace to them and, therefore, they decided to kill them and flee the country, but their plans had gone awry.
A senior officer said vital information about the incident could be elicited from those in custody, but declined to divulge what they have so far revealed.
He said all five suspects were underworld figures engaged in drug dealing.
The police also recovered a revolver and two magazines from their custody.
Another constable, an Inspector and two other civilians were injured in the shooting.