( CNN ) -- A pair of makeshift bombs blew up Thursday inside a Memphis , Tennessee , high school , sending one person to a hospital and two into police custody , officials said . The `` pressurized '' devices , which incorporated Drano clog remover , were placed in different hallways -- one on the second floor , the other on the third floor -- of Craigmont High School , Memphis Fire Department Lt. Wayne Cook said . `` What it appears is that we had a student or two do a prank , '' said Staci Franklin , a spokeswoman for Memphis schools , describing each device as a `` mailbox bomb . '' Police received a call around 11:20 a.m. CT to inform them that someone had called the school warning of a bomb , Memphis police Sgt . Karen Rudolph said . After the bomb threat , school staff heard a loud noise and saw fumes , Rudolph added . An assistant principal sought medical treatment after inhaling smoke from one of the bombs while evacuating students , according to Franklin . The injured person was taken to Methodist North Hospital in Memphis , Cook said . Franklin said the school staff member was believed to be OK. Rudolph said that no other injuries were reported . By that time , two possible suspects had been tracked down and taken into custody , Rudolph said . In addition to firefighters , Memphis police and members of the federal Bureau of Alcohol , Tobacco , Firearms and Explosives were on site Thursday afternoon , the fire department lieutenant said . Rudolph said members of the police department 's bomb unit were inside the school to clear out damage . Craigmont High School is on 50 acres in northeastern Memphis , a few miles from Interstate 40 . The school has about 1,300 enrolled students , Cook said .
NEW : 2 possible suspects are in custody , a local police sergeant says . NEW : There was a loud noise after a bomb threat was made , according to police . An assistant principal suffers smoke inhalation and is taken to hospital . It appears to be a prank , a police spokeswoman says .