Suspected Tamil Tigers shot dead two Sri Lankan Home Guards as they walked home on Friday, the army said, while a rebel-linked local politician was gunned down at work in another incident ahead of key talks.
In December and January, there were daily suspected Liberation Tigers of Tamil Eelam (LTTE) attacks on the military but they largely ceased after the two sides agreed to hold their first direct talks since 2003 in Geneva in February.
"The two Home Guards handed their weapons into the station and they were going to the village," army spokesman Brigadier Prasad Samarasinghe said. "They were shot and killed. This is a frontline village, so we suspect the LTTE."
The two sides are due to meet for a second round of talks in Switzerland in late April, but neither side trusts the other and some diplomats fear failure at the meeting could pave the way for a return to the island's two-decade civil war.
The rebels, whose fight for a Tamil homeland has killed more than 64,000 people on both sides, have repeatedly warned that without concessions they may return to battle, worrying a country still recovering from the 2004 tsunami.
The Tigers say government-backed paramilitaries have attacked them several times in recent weeks.