As many as 10 militants were killed in the Vavuniya district on Thursday, the Press Trust of India (PTI) reported.
It said six rebels were killed in the village of Kudirvittankulam, and seven militants were gunned down by Sri Lankan troops in Kallikulam.
In Thoppigala in the Eastern Batticaloa district, troops seized 1,350 hand grenades on Thursday.
The military claims to have killed a total of 501 Tamil fighters since December 1.
Liberation Tigers of Tamil Eelam (LTTE), an armed group that has been fighting for an ethnic Tamil state in the north and east of Sri Lanka since 1983, said they had prevented an attack by Sri Lankan Armed Forces (SLAF) at Muhamalai in the Jaffna peninsula on Friday morning.