At least 13 civilians including 12 children were injured in a van explosion in Sri Lanka's central district of Kurunegala Friday morning, security sources said.

Officials from the Ministry of Defence said the bomb explosion happened at around 7 a.m. (0130 GMT) at Udawalpola, Kurunegala, about 100 km northeast of the capital Colombo.

The explosion injured 12 school children and the van driver.

Officials from the Kurunegala Teaching Hospital said 12 people injured in the explosion had been admitted to the hospital.

They said four of the injured were adults and eight were children, with one child being in critical condition.

Kurunegala police said the driver had just started the vehicle when the bomb went off inside the garage of a local resident.

Sri Lankan police spokesman Nimal Mediwaka said they believed a personal dispute was behind the explosion.

This was the first major explosion after the government troops defeated Tamil Tiger rebels in May and further investigations are underway.

The rebels had been fighting for more than two decades to carve out an independent Tamil homeland in the north and east before they were defeated by the troops in May.

About 250,000 mainly Tamil civilians living in the former rebel controlled area are now being housed in several government-run welfare villages in the north waiting to be resettled to their original homes.