Two children were killed and their father was injured after a hand grenade was thrown at a house in the Kawdana area of Dehiwala, police said.
The attack took place at a residence on Sirisangabo Road, where the grenade exploded inside the premises.
Police identified the victims as two boys, aged 10 and 14. Their 52-year-old father was also injured in the explosion and was admitted to hospital for treatment.
Preliminary investigations have revealed that the attack may have been connected to a clash involving organised criminal gangs, according to police.
Three police teams have been deployed to investigate the incident and trace those responsible for the attack.
