JOHNSTOWN, Pa. (AP) -- A cloud of suspected military-grade riot gas was released from a canister near a high school Tuesday, authorities said. About 40 people were treated for exposure.
Victims reported respiratory problems, eye irritation and swelling in their faces, but no one was seriously injured, police spokeswoman Robin Melnyk said.
The gas is available only to larger police departments and the military. The FBI said it was investigating.
``There does not appear to be any nexus to any terrorist group, but our eyes are wide open,'' said special agent Jeff Kileen of the Pittsburgh division.
Police, fire and hospital officials began receiving calls shortly after 3 p.m. about a large vapor cloud in one of Johnstown's busiest neighborhoods.
A white canister more than a foot long with red lettering reading ``RIOT GAS CS'' was found in a creek about 40 feet from Bishop McCourt High School, fire Chief Mike Huss said.
Several blocks were evacuated in the area for several hours. Students and teachers that had not left the high school were kept inside for about three hours.