RPT-UPDATE 2-Sri Lanka suicide bomb kills 17 as thousands flee

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By Ranga Sirilal

COLOMBO, April 20 (Reuters) - A Tamil Tiger suicide bomber who was among thousands of civilians fleeing Sri Lanka's war zone into army-controlled areas set off a blast that killed at least 17 people, the Defence Ministry said on Monday.

At least 5,000 people burst out of the war zone on Monday after soldiers broke through a long earthen wall the Tiger rebels had built to stall their advance, the military said earlier.

"An LTTE suicide bomber has attacked thousands of Tamil civilians who are now trying to seek refuge with the Sri Lankan Army, this morning," the ministry's website said. "Battlefield sources said at least 17 civilians, including women and children, have been killed in the cowardly bomb blast."

The wall of earth had blocked the widest land link to the coastal strip where Sri Lanka's military has surrounded the Tigers with the goal of crushing them and ending a civil war that has raged since 1983 and is now Asia's longest-running.

"Troops captured the earth bund and so far 5,000 people have been rescued. It is still going on," military spokesman Brigadier Udaya Nanayakkara said.

The no-fire zone is a 17-square-km (6.5-sq-mile) area of coconut groves, where the Liberation Tigers of Tamil Eelam (LTTE) separatists are fighting their last stand from among tens of thousands of civilians they have held there by force.

The military said Monday's flight of civilians was the single largest exodus in a day.

Military sources told Reuters that the 5,000 figure given only represented those people who had been checked and cleared by soldiers for onward passage to refugee camps and the number was likely to climb later in the day.

An LTTE female suicide bomber killed at least 28 people and wounded nearly 100 in February at a refugee reception centre. But that has not stopped the exodus of people -- around 70,000 have fled LTTE areas since January.

The Sri Lankan government has been under heavy Western pressure to call a ceasefire to protect people in the no-fire zone, since the LTTE has rejected all international calls to let them go and insists civilians are staying by choice.

Sri Lanka has rejected further calls for a truce after the expiration of a 48-hour pause last week, saying the Tigers only used it to bolster their defences and make it harder for people to escape. (Writing by Bryson Hull; Editing by Bill Tarrant)