COLOMBO, March 31 (Xinhuanet) -- Four epidemiological teams from the capital Colombo have left for the central region to investigate the sudden death of two students and the vice principal of a rural school in Badulla, the official Daily News reported Thursday.

    Although the exact cause of the students' deaths have not been established in the initial postmortem, local medical officials said there was no reason to believe that the deaths were linked to a mystery disease.

    "We are not sure of the cause of deaths of the two students butthe Vice Principal R.M.Gunapala, 52, had died of a heart attack," district medical officer of Wewegama Hospital, Susantha Kariyawasam said.

    The first student, Sanath Premasiri, 16, had high fever and was vomiting.

    He received medical treatment a few days before his sudden death. He was pronounced dead on admission to hospital on March 23."However, he had not been ailing at the time," Kariyawasam said.

    Dhanushka Chaturanga, 16, who was in the same class had complained that he was feeling faintish at school on March 28 and was admitted to Wewegama hospital by the vice principal. The postmortem had not detected a possible cause of death.

    Kariyawasam has ruled liver and goal bladder enlargement as thecause of Sanath's death while the investigation on the cause of the other two deaths was still underway.

    The local authority has closed four schools in Badulla region until the investigation ends. Enditem