Classes were held as usual at Clifton School No. 11 in Clifton following the discovery of a plot by five fifth-graders to allegedly attack Clifton High School with a makeshift explosive.

Parents at the school on Thursday morning told CBS New York they were upset because they were not notified about the incident.

“I’m really surprised by this, we should have been notified" said one father.“I need to speak to the principal or someone in charge — I don’t even know if I’m going to leave them in school today.”

Staff at the school on Wednesday morning notified police of the discovery of written plans to use a device — which police have said was filled with vinegar and cinnamon, and could not have actually exploded. The students brought the device to their elementary school and were planning to use it during a field trip to Clifton High School, police said.

The students, ages 10 and 11, were suspended from school and  turned over to their parents. No charges have yet been filed.

News 12 New Jersey reported that police say the students may have received help from someone else developing their plan.

No notice about the planned attack was posted to either School No. 11's or Clifton High School's websites Thursday.

Calls by New Jersey 101.5 to the Passaic County Prosecutor's Office, Clifton Police and Superintendent of Schools Richard Tardalo have not yet been returned.