The conflict has claimed more than 60,000 lives since 1972.
Two men were shot dead early Tuesday in Batticaloa district, 300 kilometres (190 miles) east of Colombo, the military said, adding that investigations were underway.
Elsewhere, unidentified gunmen shot dead a 31-year-old local aid worker attached to a government agency in the eastern district of Ampara on Tuesday, police said.
In the northeastern district of Vavuniya, 260 kilometres (160 miles) north of here, suspected Tiger rebels gunned down a man inside his home late Monday, the defence ministry said.
Six people were gunned down in the same district at the weekend.
The military blamed the Tamil Tigers for the four deaths, but the rebels denied involvement.
Government forces are trying to eject the rebels from large swathes of jungle in the east. The rebels also run a mini-state in the north of the island.
The majority Sinhalese and the minority Tamil communities are currently marking their common New Year festiv