Sri Lanka's Tamil Tigers told the government today to immediately withdraw from a rebel stronghold it seized this week or face war.
The army captured the territory on the southern edge of the strategic Trincomalee harbour on Monday after days of artillery battles. It was the first major capture of territory by either side since a 2002 ceasefire.
"We perceive the Sri Lankan armed forces occupying our territory as tantamount to a declaration of war," S Puleedevan, head of the rebels' peace secretariat, said.
He said the Tigers would launch a counter-attack and "evict" the army from Sampur if it did not withdraw immediately, adding that the ceasefire agreement was "in tatters".
"The conflict is already widening all over the northeast, the Tamil homeland," Puleedevan said. "So far, we have tried very hard to maintain restraint, not to launch offensive attacks, but there are limits."
Until now, and despite heavy fighting in recent weeks, the government and the rebels had been insisting that they continued to stand by the terms of a 2002 truce.
But the each side blame the other for trying to force a full-scale return to a war that has killed more than 65,000 people since 1983.
On Wednesday, the rebels' political chief met the Norwegian ambassador and mediator Hans Brattskar in the northern town of Kilinochchi and said the ceasefire had effectively been destroyed by the seizure of Sampur.
The latest episode in Sri Lanka's two-decade civil war began with air strikes on rebel territory in late July amid a dispute over a blocked water supply. The fighting then spread to Jaffna.
Hundreds of civilians, troops and Tiger fighters have been killed in the past month, and more than 200,000 people have been displaced and are living in refugee camps across the island's rural northeast.