( CNN ) -- Northern Michigan University officials say the situation `` is under control '' after a telephone threat against students , faculty and others prompted a lockdown of the Marquette , Michigan , campus Wednesday morning . However officials continued to urge students to remain in their dormitories and visitors to stay away from the campus until further notice . The administration closed the university at 8:20 a.m. Wednesday after campus police learned of a telephone caller who had earlier threatened to attack NMU . Cindy Paavola , the university 's director of community relations , said campus police took the threat seriously , thus prompting the administration to close the university as a precautionary measure . `` The caller threatened that there would be harm to students , faculty , staff and administrators , '' Paavola said . `` They did n't identify particular people , but it was a wide-ranging threat and we are taking it seriously . '' `` We do n't know the seriousness of the threat because we have n't caught up with this person . Rather than be sorry , we 're going to be safe , '' Paavola said . State and local law enforcement authorities are assisting university police in the investigation , she added . The Marquette Area Public Schools also sent students and staff home , interim superintendent Debra Veiht told CNN . She said police referred to a threat on a blog , which they deemed credible . `` We put in our emergency plan into place and it 's running smoothly , '' Veiht said . The public school system has more than 3,000 students and 400 staff members , she said . The Marquette Senior High School is located about a half-block away from the university . University officials locked down all buildings so no one could enter or leave , and told students living on campus to stay in their dormitories . Paavola said several office buildings were evacuated Wednesday morning . CNN 's Chris Kokenes contributed to this report .
NEW : Northern Michigan University officials say situation is under control . Officials continue to warn students and faculty not to wander on university grounds . Police put the campus on lockdown early Wednesday because of threat against students , others . Public schools in Detroit were also closed , the interim superintendent said .