What is the cause of death of 12 Bateq.

What is the cause of death of 12 Bateq, Kampung Sungai Koh, Gua Musang, Kelantan, Malaysia?
     Universiti Malaysia Kelantan is studying the poisons such as arsenic, cadmium and mercury in river at Kampung Sungai Koh. We hope that the authorities confirm the finding of the university.