The fighting was part of a major escalation in attacks between the two sides along the front lines surrounding the Tamil Tigers' de facto state in parts of the north. Government officials say they aim to crush the rebels in a bid to end more than two decades of warfare on this Indian Ocean island.
In two battles Wednesday, troops killed nine rebels in the Muhamalai area of the Jaffna peninsula, north of rebel-held territory, the military said in a statement Thursday. The army killed four more rebels in two other attacks in the area, while another rebel was killed in a confrontation in the Mannar district south of rebel areas, the AP reports.
The violence - along with the previously announced deaths of nine rebels - brought the toll from fighting Wednesday to 23 rebels killed, 18 of them in the fighting in the Jaffna peninsula, according to military figures.
Rebel spokesman Rasiah Ilanthirayan disputed those figures, saying that only one rebel was killed in the Jaffna fighting Wednesday.
In other violence, rebels detonated a land mine alongside a major road in the north Thursday morning as a road clearing patrol passed, killing a police officer, said Brig. Udaya Nanayakkara, the military spokesman.
The fighting came as Japanese peace envoy Yasushi Akashi traveled to a peace conference of religious leaders in the turbulent city of Jaffna. Akashi was not expected to launch any new peace initiatives during his visit.
The rebels have fought since 1983 for an independent homeland for ethnic minority Tamils after decades of discrimination under governments controlled by the Sinhalese majority. More than 70,000 people have been killed in the conflict.