Sri Lanka's military said on Thursday its war planes had "completely destroyed" a rebel hideout near the northern town of Kilinochchi where Tamil Tiger leaders were meeting.
"Sri Lanka Air Force fighter jets targeted an LTTE (Liberation Tiger of Tamil Eelam) senior leaders' gathering at Jayapoor in Kilinochchi," the defence ministry said in a statement.
"Pilots confirmed that the location was completely destroyed," it added.
The pro-rebel TamilNet website however said the bombs hit a civilian area in Kilinochchi, the main town in the rebels' northern mini-state, wounding seven people and damaging nine houses.
It said the planes "bombed a civilian area with a mechanic workshop," and that Tamil Tiger rebels responded with anti-aircraft fire.
No independent confirmation of the conflicting accounts of the raid was available, and the Sri Lankan government has barred journalists from visiting the rebel-held north.
The air strike came hours after a truce, signed by the LTTE and the government in 2002, officially came to an end at midnight on Wednesday.
It also came the day after the Tigers were blamed for a public bus bombing in the south which killed 27 civilians and wounded more than 60 others, according to a new toll issued by authorities.
Six farmers were also reported to have been shot dead by an LTTE unit in the same area.
The Sri Lankan government pulled out of the ceasefire arguing the Tigers, who want to carve out an independent state in the north and east of the island, had only used the truce to re-arm.
Fighting has been escalating over the past year anyway, and Nordic peace monitors said late last year that they had lost count of violations of the Norwegian-brokered ceasefire.
The truce monitors pulled out of Sri Lanka on Wednesday, with a warning to both sides that the long-running war cannot be won.
Defence officials in Colombo have spelled out their determination to kill LTTE supremo Velupillai Prabhakaran, who has been leading a rebellion against the island's ethnic Sinhalese majority since 1972.
In November, Sri Lankan government jets managed to kill LTTE political chief SP Thamilselvan in a bombing raid, and the island's military began the New Year with a vow to kill 3,000 guerrillas in the first six months of the year.
The defence ministry said fighting was meanwhile continuing across front lines in the north, with the military claiming to have killed six more rebels.
Colombo claims it has killed 411 rebels since the start of the year against 20 soldiers killed. The figures cannot be independently verified.