( CNN ) -- Campus police at the University of South Florida were questioning two men in connection with back-to-back incidents on the school campus Monday . Police take a man into custody at the University of South Florida after receiving reports of a person with a bomb . Investigators were questioning one man following a report of an armed intruder , USF police Lt. Meg Ross said . And a second man was also being questioned following a report of a man carrying a large hunting knife and a puppy , she said . USF police asked the Tampa police 's bomb team to respond to the campus regarding a backpack belonging to man in the first incident , said Ross . No one was hurt , she said , and no shots were fired . `` We have someone we think may have been involved , '' Ross told CNN , `` but we have to investigate fully . '' `` We have not looked in his backpack , '' she added . `` We have the bomb squad on their way to look at that . '' Police received a report that a person armed with a bomb and a gun was in the area of the university 's library . Authorities later received a report of a subject on a bus in the area of the university 's Parking and Transportation Services , Ross said . `` We checked the area at the library , did not locate him , but then received a subsequent report of a subject on a bus , '' she said . The campus stayed on lockdown after police received a report almost immediately after taking the first man into custody of a man wearing a black tank top and a cowboy hat , carrying a knife and a black puppy . `` We 're questioning him , '' Ross said . `` We do not believe he is related to the first incident with the backpack . '' Text messages were sent out to 13,000 employees and 45,000 students to warn them after the first incident , and emergency sirens on campus also were activated , officials said . But Ross said that the campus had been given the all-clear , except for the shuttle-bus area -- where the first subject was taken into custody -- while Tampa Police examined the backpack . CNN 's Rich Phillips contributed to this report .
Campus police question 2 men after incidents on school campus campus . Report of armed intruder on the University of South Florida campus in Tampa , Florida . Police received a report of person armed with bomb , gun near the campus . Campus police say no one was hurt , no shots were fired .