COLOMBO, April 28: A massive explosive device placed in a bus station was diffused on Monday minutes before it exploded, authorities confirmed three days after a bus bomb left 26 dead and scores injured.

Military spokesman Brigadier Udaya Nannayakkara said a ball-bearing packed time-bomb capable of causing mass scale destruction was defused in northwestern Galgamuwa100 kilometres north of Colombo.

The bomb was detected by passengers at the Galgamuwa bus station, Nannayakkara said.

Meanwhile, the official army website said many other explosives and bombs were unearthed from several locations throughout the country as troops and police combed each district for hidden explosives and suspected Tamil Tiger rebels as heavy fighting mounted in the north.

Troops recovered one claymore mine, one detonator and a claymore mine stand in Nunavil in Jaffna while two T-56 magazines, and other ammunition were detected in eastern Batticaloa, the military website reported.

Separately, the Air Force Monday bombed a building complex adjoining the LTTE airstrip in Tiger guerrilla-held territory, military officials said.