An unidentified disease has killed 60 children in Cambodia in three months, the World Health Organization (WHO) said Tuesday as it seeks to identify the cause. “The number of deaths reported to WHO is 60 cases, and they have all been in young children," Dr Nima Asgari, a public health specialist for the U.N. body in Cambodia, said, adding that the first casualties were reported in April. The WHO is currently working with the Cambodian Ministry of Health “to identify the cause and the route of spread of this disease," Asgari said. With the investigation still at an early stage, Asgari said it is difficult to specify the symptoms, which “include high fever and severe chest disease symptoms, plus in some children there were signs of neurological involvement." There have been 61 reported cases so far, Asgari said, with just one patient having survived. The victims, all aged seven and under, were admitted to hospitals in the capital Phnom Penh and the northwestern tourist hub of Siem Reap.