Security forces have captured two of the Tamil Tigers' most wanted fighters along with six of their accomplices, defence sources said yesterday. Police said the arrests at the weekend of the two rebel leaders, in the Greater Colombo area and in the North Central Province, represented a major breakthrough for the country's security forces. Police and army intelligence have launched a full-scale hunt for a haul of powerful explosives in Colombo and the north-central town of Anuradhapura following the arrests. Investigators said the two hard-core rebels, Illanko and Selvarajah, had been identified as leaders of the elite Liberation Tigers of Tamil Eelam suicide squad. Illanko had planned to lead a team of Black Tiger guerillas to destroy one of Sri Lanka's holiest Buddhist shrines, in the sacred city of Anuradhapura. Three others, suspected to be members of a 10-man suicide squad, were arrested along with him while travelling in a lorry towards their designated target. Police said the four suspects arrested in the Greater Colombo area of suburban Dehiwela had confessed to having stashed a large consignment of arms and explosives in rebel safe houses in the metropolis. The explosives were said to have been smuggled into the city concealed in sacks containing onions. Four sacks were discovered in the home of the suspected Black Tiger leader, Selvarajah. The three others in police custody are women. Security officials said the missing consignment of arms included rocket-propelled grenades, mortars and plastic explosives. Two of the suspects had disclosed a detailed plan to blast vital installations, public institutions and population centres, according to police. Police teams were attempting to locate the safe houses from where the missing arms and explosives were to be supplied to the Tiger hit squads. A senior police source said the threat of Tiger hit squads planning a bombing spree in the city was a matter of grave concern, although there had been no lifting of the massive security blanket which came down on the capital last week.