Sri Lanka's military pounded Tamil rebel territory in the north with airstrikes and artillery after army bases came under heavy fire from the Tamil Tigers, an official said on Saturday.
"The (rebels) began attacking us on Thursday. We have been retaliating since then," military spokesman Brig Prasad Samarasinghe said.
Samarasinghe said the attacks continued through Friday night, but he did not immediately have details about Saturday morning.
Several soldiers suffered minor injuries in the exchange of fire near Kilali, close to the de facto border between government and rebel-held territory in the north, he said.
There was no immediate word from the separatist Liberation Tigers of Tamil Eelam about casualties.
Jaffna has long been a flash point for violence in the country's nearly two-decade civil war between the Sinhalese-dominated state and ethnic Tamil rebels who consider Jaffna to be the heart of Tamil culture.
The Tigers lost control of the peninsula in 1995 but still hold vast swaths of territory in the north, just south of Jaffna, and along the northeast coast, which they want as a separate state for ethnic Tamils.
The 19-year conflict cost the lives of about 65,000 people before a 2002 ceasefire.
The truce is now on the verge of collapse as months of escalating shootings and bomb blasts morphed into near-daily airstrikes and mortar fire.