An investigation is underway at Essex Agricultural and Technical High School in Danvers, Mass., where more than a dozen students have been experiencing bizarre vocal tics or hiccups, the Salem News reported.

The Massachusetts Department of Health is working with local health officials in order to better assist the community.

However, Peter Mirandi, the health director for Danvers, said that no physicians have officially diagnosed or confirmed any of the students’ cases – meaning health officials cannot determine a specific cause just yet.

“I have no confirmed cases of something; we don’t know if it’s a contagious disease or an environmentally induced disorder. It’s not responsible for me to say anything further on it,” Mirandi told the Salem News.

The vocal tics began between November and December of 2012, when two to three parents contacted Mirandi’s office about their children.

The situation is similar to a scenario that occurred Le Roy High School in upstate New York, where 12 girls suffered from tics comparable to Tourette syndrome.  An investigation into the incident did not reveal any environmental causes for the ‘outbreak,’ leading one doctor to assume the girls may be suffering from mass hysteria brought on by stress.

Click for more from the Salem News.