The Sri Lankan air force has bombed a Tamil Tiger rebel training camp in Vavuniya, in the north of the country, according to the defence ministry.
A defence ministry spokesman said the air force also hit a rebel position.
The rebels denied any of their military positions were hit and alleged that two civilians were killed in the bombing.
Violence has risen in Sri Lanka in recent months as the country has slid back towards war, despite a 2002 ceasefire still in place.
"We have taken two identified targets which were primarily a training camp of the rebels and the other was a gun position from where they were targeting our troops," spokesman Brig Prasad Samarasinghe was quoted by news agency Reuters as saying.
The agency said the Tamil Tiger spokesman Rasiah Ilanthirayan denied the statement.
"The so-called training centre that the Sri Lankan state is saying is a civilian area, and until now we have recovered two bodies of civilians," he said.
The conflicting claims have not been independently verified.
Mr Ilanthirayan also accused the Sri Lankan forces of setting off a landmine attack in another Tiger-held area.
"The attack was against a van which was carrying about 20 passengers," he told news agency AFP.
"Fortunately, the passengers escaped unhurt," he said.