Two more bodies were found with ropes around their necks on the bank of a lake in the same town, Dharmadasa said. Police had yet to establish their identities.
"They appeared to have been strangled," he said.
The government meanwhile reaffirmed its commitment to the peace process and urged the Tigers to resume negotiations.
In a statement, a spokesman at the defence ministry's media centre for national security said late on Saturday: "The government reaffirms its total commitment to a peaceful settlement for the north and east.
"The government appeals to the international community to condemn such acts of terror and prevail on the LTTE [Tamil Tigers] to renounce violence and return to the negotiating table."
Three people were detained on Saturday for questioning in connection to two bus bombs that have been blamed on Tamil separatists in which at least 21 people were killed and dozens were wounded.
Security forces said that a Tamil Tiger bomber killed at least 15 people and wounded 40 more on a bus in the coastal town of Meetiyagoda, 95km south of the capital, Colombo, close to several popular resort towns.
Less than 24 hours earlier, a bus bomb also blamed on the Tamil Tigers killed at least six people just northeast of Colombo.