Doctors in Cambodia say they have identified an illness that has killed dozens of children in the past three months.

Officials at the Cambodian Health Ministry and the World Health Organization announced Sunday that samples collected from some of at least 60 children who died, tested positive for the Enterovirus 71, which causes hand, foot and mouth disease. It is spread through contact with mucus, saliva or feces of an infected person.

The United Nations health body and Cambodian officials are urging parents to bring their children to a hospital if they see signs of any unusual illness. There have been no cases reported outside Cambodia, so far.