The defence ministry said the rebel Liberation Tigers of Tamil Eelam (LTTE) attacked police commandos in the island's east, wounding four. One of them died in hospital, the ministry said.

It added six guerrillas were also killed by commandos in the firefight in the district of Ampara. Both sides also traded long-range attacks in the neighbouring district of Batticaloa, but there were no immediate reports of casualties.

The pro-rebel Tamilnet website said the Sri Lankan government had scuttled the peace initiative by asking Oslo to suspend its contacts with the rebels, which prompted the Norwegians to call off a planned meeting.

"Analysts view the move as a step to effectively nullify the already defunct Ceasefire Agreement," Tamilnet commented, the day after Colombo asked Norway to scrap a meeting set for Tuesday with guerrilla leaders.

The government is also considering reactivating the tough Prevention of Terrorism Act after Friday's suicide bombing against Defence Secretary Gotabaya Rajapakse, the younger brother of President Mahinda Rajapakse.

There has not yet been any official comment from the LTTE, although last week Tiger supremo Velupillai Prabhakaran wrote off four years of peace talks by saying the Oslo-brokered truce was "defunct".

Norwegian envoy Jon Hanssen-Bauer was told his planned visit to the rebel-held town of Kilinochchi Tuesday would not meet with Colombo's approval, the top government official dealing with Norway, Palitha Kohona, said Sunday.

"The cabinet of ministers will review the government's relations with the Tigers on Wednesday," Kohona told AFP. "Until then, we don't want the Norwegians to have any contacts with them."

The toughened government stand comes after months of worsening violence and growing pressure from nationalists and key allies of the government to declare the Tamil Tiger rebels a terrorist group.

Groups opposed to the rebels held rallies on Sunday and put up posters across the capital at the weekend demanding that a ban on the LTTE, lifted in 2002 when the peace initiative kicked off, be reinstated.

The Tamil Tigers have been campaigning for independence for the island's minority 2.5 million Tamil community in the majority Sinhalese nation of 19.5 million people.

More than 3,400 people have been killed by the conflict in Sri Lanka in the past year, and the bitter ethnic conflict has claimed more than 60,000 lives since 1972.