Updated

Sri Lanka's military says an explosion in a passenger bus has injured 19 people, including 12 military personnel.

Brig. Sumith Atapattu said the explosion occurred Wednesday near Diyatalawa, a former garrison town about 190 kilometers (120 miles) from the capital, Colombo. The explosion and fire that followed caused severe damage to the bus.

He said the cause of the explosion is still not known, but it is possible that someone may have been carrying a grenade.

Atapattu said police and the military are conducting separate investigations.

There were frequent bomb explosions in public transportation vehicles during the country's long civil war, but Atapattu said there was no evidence of terrorist involvement.