A leading Buddhist priest of the Kotte Rajamahavihara Temple and another monk were murdered a short while ago, the police said.
According to initial reports the assailants had arrived in a car and stabbed the two monks before making their escape.
The monks were identified as Pitigala Jinarathana thero (80) and Borelesgamuwa Gunarathana thero (60).
One monk died at the location while the other died on admission to the Kalubowila hospital.
The police said that eyewitnesses had identified the number plate of a vehicle believed to have been used to commit the crime.
A tense situation prevailed in the area as a result of the double murder.
Police investigators, with the assistance of a sniffer dog, later arrested four people on suspicion from a house adjoining the Temple.
A large crowd gathered around the area although it was past midnight and demanded that the police show the identity of the suspects arested.
The police however refused to do so insisting that the four people are only to be questioned as suspects.
Once the suspects were taken away the crowd dispersed.
Pics by Easwaran Rutnam