Three people were shot dead and another injured in an equal number of separate daylight incidents that took place in the Metropolis and elsewhere in front of horrified bystanders, during the week, police said.
They said in the first incident one person was killed and another injured at Bastian Mawatha in Pettah on Monday shortly after they had attended a court hearing.
Two assailants astride a motorcycle had opened fire on the victims with a semi-automatic assault rifle before fleeing the scene.
The pair was rushed to the Colombo National Hospital. One person later succumbed to his injuries. According to police the victims are residents of Anuradhapura.
The duo had earlier filed a compensation claim case against their former employer who had discontinued their employment three months ago, according to investigators.
However, the employer too had filed a court case against the victims for alleged fraud.
On Friday a king coconut trader and a vegetable vendor were shot dead in broad daylight at Panadura and Beruwala.
In both incidents the killers had arrived on motorcycles, police said.
Randika Madhushan, 30, a vegetable vendor in Panadura town and a father of two, died instantly in the attack at Nirmala Mawatha in Panadura.
The victim was targeted as he rode his motorcycle towards the Galle Road, police said.
He was a resident of Thalpitiya, Wadduwa.
In the other incident, a 42-year-old king coconut trader was shot dead as he sat in the driving seat of his parked vehicle at Moragalla in Beruwala.
The man, who was not identified, was a resident of Maradana, Beruwala. Investigators believe that the killings had been triggered over monetary transactions but they were also probing for other reasons.