Hazardous materials team members process material removed from a civil engineering building at the University of Missouri-Rolla. A graduate student claiming to possess anthrax and a bomb threw the south-central Missouri community of Rolla into a panic Tuesday, but police suspect it was an empty threat by a depressed student and not an incident of terrorism.

Rolla, Mo. ? A University of Missouri-Rolla graduate student claiming to possess anthrax and a bomb threw this south-central Missouri community into a panic Tuesday, but police suspect it was nothing more than powdered sugar and an empty threat by a depressed student.

The student’s name was not released. Interim Police Chief Mark Kearse said he was an international student but did not give his name. He said the man was despondent about his grades.

“Thankfully this is a false alarm,” said Chancellor John Carney III, adding that the downside was that the university lost “a precious day of classes.”

Campus spokeswoman Mary Helen Stoltz said classes would resume today.

Kearse said charges could be filed later Tuesday.

Preliminary tests on a white, powdery substance found on the student showed it was powdered sugar, said Lt. Col. David Boyle of the Missouri National Guard’s 7th Civil Support Team at Fort Leonard Wood. The substance also was found near a desk in a room of the Butler-Carlton Civil Engineering Building where the student was arrested.

The substance was sent to a laboratory for further tests, Boyle said. “We personally expect those to come back with similar results,” he added.

Twenty-three people – eight students, a faculty member and emergency workers who responded to the call – who had been quarantined because they could have come in contact with the substance were released. Ray Massey, ambulance director at Phelps County Regional Medical Center, said none showed signs of illness.

The incident started shortly after 2:30 a.m. when police were called about a man making a threat. They arrived to find the student holding a paper bag and a knife. He said he had planted a bomb and said he had anthrax, Kearse said.

When the man refused to drop the knife, a university police officer shot him with a stun gun, and the man was arrested.

The 5,850-student technological research and engineering campus was shut down during the incident and classes were canceled for the day while officers investigated. A Catholic grade school near campus also was closed for the day.

Police found a four-page note in which the student threatened to destroy the building, Kearse said.

The man’s identity and nationality were not released, though school spokesman Lance Feyh confirmed he was an international student. The man was decontaminated and taken to a hospital before being taken to a holding facility at the Rolla Police Department, Kearse said.

The Fort Leonard Wood Explosive Operations Division was investigating the possibility that a bomb may be in the engineering building. Kearse said authorities were double-checking the building Tuesday afternoon to make sure a bomb wasn’t there.

“We have no hard evidence that there’s anything wrong in the building, but we simply can’t take a chance,” Mayor William Jenks said. “We’re taking a very cautious approach.”