Nicosia, May 28 (IANS) A 28-year old Canadian citizen of Lebanese descent was remanded in custody over the possession of an unusually large quantity of ammonium nitrate, a chemical compound used for preparing explosives, Cyprus's police said on Thursday. A police spokesman said almost two tonnes of the chemical was found in the basement of his residence in the southern city of Larnaca. A police spokesman said the case under investigation is "a very serious one and is being dealt with very carefully by the police", Xinhua news agency reported.