A suspicious letter that prompted a police and fire investigation at the University of Hawaii at Manoa campus on Wednesday turned out to be harmless, a fire department spokesman said.

After a two-and-a-half-hour investigation, firefighters turned the letter over to Campus Security after determining the letter did not pose any hazards, said Honolulu Fire Department Capt. Terry Seelig.

Police said Campus Security called about the suspicious item about 8:50 p.m. Wednesday, and a police bomb squad was sent to check the item for explosives. The fire department’s hazardous materials company waited for bomb squad to finish its investigation before testing the letter for biological or chemical hazards.

Seelig said Campus Security reported the letter was found in Hamilton Library and brought outside.