(AFP) - Heavy fighting between government troops and Tamil Tigers broke out in northern Sri Lanka Thursday, hours after Colombo announced it was pulling out of a tattered ceasefire agreement with the rebels.
At least six Tiger rebels and a government soldier were killed in the latest clashes along the de facto border of the mini-state run by the Liberation Tigers of Tamil Eelam (LTTE), the defence ministry said.
For their part, the Tigers said they beat back a military offensive into their territory and claimed they killed 10 government soldiers and wounded 15 more. The rebels said in a statement that they did not suffer any losses.
Both sides are known to claim heavy losses for their adversaries and there is no independent verification.
In the capital Colombo, the already tight security was further strengthened one day after suspected LTTE rebels set off a roadside bomb targeting an army bus that killed five and wounded 28.
Two government soldiers were also killed and three wounded in another mine attack in the north-central part of the island on Thursday, police said.
An opposition Tamil lawmaker who was gunned down on New Year's Day at a Hindu temple was cremated in Colombo Thursday amid heavy security and protests by human rights groups, which hold the government responsible for the slaying.
The government has denied involvement.
On Wednesday night, Sri Lanka announced it was formally pulling out of the Norwegian-brokered 2002 ceasefire agreement, after months of escalating violence and with authorities believing they now have the upper hand in the decades-old conflict.
The government Thursday said it had given the mandatory two weeks' notice to Norway, which means it will quit the truce from January 16. It said the Norwegian-led Sri Lankan Monitoring Mission (SLMM), which has monitored the truce, would also be dissolved.
Government spokesman and media minister Anura Yapa said the government viewed the 2002 truce agreement as a "flawed document."
"The government does not want to be a party to a non-functioning ceasefire agreement," Yapa told reporters here. "But it does not imply that the government has shut the door for negotiations."
He said that if the Tamil rebels were to lay down their arms -- an unlikely event -- the government could resume talks facilitated by Norway, which broke down in October 2006.
UN secretary-general Ban Ki -moon Thursday deplored the move and pleaded for an end to the bloodshed through a political solution. His press office said in a statement: "He is deeply worried that the withdrawal from the agreement comes amidst intensifying fighting in the North and increasing violence across the country, including Colombo."
Ban appealed to the warring sides to ensure the protection of civilians and allow the flow of humanitarian aid to areas affected by the fighting.
And Canada's Foreign Affairs Minister Maxime Bernier on Thursday said in a statement that he "deeply regrets the decision".
Norway's International Development Minister Erik Solheim , an architect of the 2002 truce, expressed his concern over the possibility of a slide back into all-out war.
Sri Lankan military chiefs have promised an imminent turning point in the war and have vowed to eject the rebels from their mini-state in the tropical island's northern Wanni jungles.
Under the ceasefire that went into effect from February 23, 2002, both the Sri Lankan government and the Tamil Tigers had the option to pull out after giving two weeks' written notice to the Norwegian foreign minister.
There was no response from the Tigers -- although LTTE leader Velupillai Prabhakaran had already said in November that the peace process was a waste of time.
The truce had initially halted the daily death toll but both sides have been drifting back towards all-out war since the collapse of talks in October 2006.