The elephant had attacked the van, plying on the Puttalam-Anuradhapura Highway, near the Mee Oya Bridge at Karuwalagaswewa area in the wee hour of the morning after the van had collided with the elephant on the road, according to the police.
One passenger was killed at the scene while the five-year-old boy, who was critically injured, succumbed to his injuries after he was transferred to Colombo National Hospital from Puttalam Base Hospital.
Two women and seven men injured in the attack were admitted to the Puttalam Base Hospital while a four-year-old child who was in critical condition was later transferred to the Colombo National Hospital.
State-run television reported the passengers, in the van were residents of Jaffna and they are on their way from Jaffna to the Katunayake Airport.
The Karuwalagaswewa Police are conducting further investigations.