The World Health Organization is investigating the deaths of at least 64 children in Cambodia. The reported deaths occurred after the kids suffered severe neurological and respiratory symptoms.

Dr. Beat Richner from the Kantha Bopha Children’s Hospitals explained that out of 66 known cases, only 2 patients have survived. The mysterious illness has appeared only in children, and a majority of the reported cases were related to children under 3. The kids usually experienced a high fever that intensifies into respiratory and neurological complications, which includes convulsions and encephalitis, the inflammation of the brain.

“They are hospitalized,” Richner explained. “They arrive in our hospital; in the last moments … they die because their lungs are destroyed.”

“I think our idea is an enterovirus or an intoxication of a drug,” Richner responded when asked about a possible cause.

“The investigation is ongoing. We are looking at detailed information from the hospital records and analyzing each and every case. We hope to have a better picture in the coming days,” explained Dr. Ly Sovann from the health ministry.

Countries around Cambodia, including Hong Kong have been alerted of the trending disease, and officials are now watchful of children showing respiratory symptoms after returning from Cambodia.