The navy has seized high explosives from a fishing boat along with eight detonators in northern Sri Lanka [Images], as a Tamil teenager was fatally shot by suspected Tamil Tiger rebels in the country's east, the military said on Tuesday.

The explosives and detonators were uncovered in Jaffna on Monday by navy officers who were suspicious of the boat, said Brigadier Daya Ratnayake, the military spokesman. The three occupants of the boat were arrested.

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Ratnayake said the explosives had the potential to 'cause substantial damage'.

In a separate incident on Monday night near eastern Batticaloa, three suspected Tamil Tiger rebels shot and killed Madawaraja Pirav, 17, Ratnayake said.

Pirav was associated with the breakaway faction of the mainstream rebel group. The Tamil Tigers began fighting in 1983 for a separate homeland for minority ethnic Tamils in the country's north and east, claiming discrimination by the majority Sinhalese.

The conflict killed nearly 65,000 people before a 2002 cease-fire. The truce has held, but the peace process has stalled due to disagreements over the rebels' demands for wide autonomy. Also, scores of people have been killed in eastern Sri Lanka since a split in the rebel movement a year ago.