Sri Lanka killings go on, Nordic envoy talks peace

COLOMBO, May 25 (Reuters) Suspected Tamil Tiger rebels killed four policemen in a mine ambush today and shot another dead, as Norway's special peace envoy met Sri Lanka's President in a diplomatic push to avert a return to civil war.

The attacks underlined the challenges that envoy Jon Hanssen-Bauer faced in trying to coax the Liberation Tigers of Tamil Eelam (LTTE) back to the negotiating table.

More than 270 people have been killed since February in what truce monitors and the Tigers say is now a ''low-intensity war'', including more than 20 security forces personnel and civilians in the past week.

Many residents fear a return to the two-decade civil war that killed more than 64,000 people before a 2002 truce.

In Colombo, police cordoned off the heart of the capital's business district, citing an unspecified security threat, and stopped cars from approaching the World Trade Centre -- home to the stock exchange and the government peace secretariat.

A claymore fragmentation mine in Kattankudi in the eastern district of Batticaloa killed four Special Task Force officers in a van, said a police source, who asked not to be named.

A policeman was then shot and injured when a team was sent to the scene to investigate, and five soldiers were injured in two separate claymore fragmentation mine blasts in north-central Sri Lanka. Another policeman was shot dead by suspected rebels in the east.

A senior rebel commander was killed in a separate blast in the north, which the Tigers said was a training accident.

Artillery, mortar exchanges and firefights are now commonplace near forward defence lines in the north and east, where the rebels want to carve out a separate homeland for ethnic Tamils.

The Tigers yesterday said Hanssen-Bauer's visit was unlikely to yield much given the upsurge in violence.

A senior aide to President Mahinda Rajapakse said his meeting with Hanssen-Bauer had been a cordial briefing, but analysts expect little progress on the peace front. The envoy also met with prominent Buddhist monks.

Hanssen-Bauer was due to meet more government officials and civic leaders tomorrow before heading to the northern rebel stronghold of Kilinochchi on Saturday.

''The situation is very serious and it looks as if we could ... revert to an all-out conflict, so let's hope that the Norwegians are successful in trying to at least prevent the situation from getting worse,'' said Rohan Edrisinha of the Centre for Policy Alternatives.

The Tigers accuse the army of helping a breakaway band of former rebels to attack them, and say ambushes and assassinations must stop before any peace talks can resume.

Diplomats say the European Union is poised to label the Tamil Tigers as a terrorist organisation this month after a series of attacks on the military, including the worst naval clash since the ceasefire -- which still technically holds.

REUTERS SI RAI2150