(CNN) -- Students at Louisiana State University were allowed back into their dorms Monday night, hours after the Baton Rouge campus was evacuated due to a bomb threat.
Law enforcement officers have been on high alert since a call came into the East Baton Rouge Parish 911 center at 10:32 a.m. (11:32 a.m. ET) with an unspecified threat about a bomb on school grounds, university spokeswoman Christine Calongne said.
That prompted a campus-wide evacuation as well as a building-by-building search by law enforcement officers. In a 4:45 p.m. press conference, LSU police Capt. Cory Lalonde indicated school buildings would reopen individually, once they are deemed safe.
By around 8 p.m., all residential life facilities on the LSU campus were back to normal operations and students were allowed back in, according to a notice posted on LSU's Twitter feed. Two dining halls also reopened.
"Notifications on other campus facilities will be made as appropriate," the university's message said, without elaborating on how the situation might affect class schedules Tuesday. "Keep your travels on campus restricted to (reopened) facilities until further notice."
Calongne, a university spokeswoman, earlier told CNN that no specific buildings were mentioned in the 911 call, and Lalonde added hours later that it is "a little too early to speculate on motives."
The threat led to interim President William Jenkins' decision to clear the campus, which the university initiated with a campus-wide alert telling students and staff to "please evacuate as calmly and quickly as possible."
"The decision had to be made to clearly protect those for whom we are responsible -- our faculty, our staff, our students and those visiting our campus," said Jenkins, who is also interim chancellor at Louisiana's flagship university. "We cannot place anyone at risk with a threat such as this."
Authorities did not indicate how many people were affected by the evacuation order, though LSU's website indicates more than 26,000 students are enrolled. A state police SWAT team was sent to help with the evacuations and bomb sniffing dogs were on site, said state police Sgt. Len Marie.
Col. Michael Edmonson said the campus, including a K-12 school that itself has 1,360 students, was effectively cleared within "about 45 to 50 minutes," a coordinated response that he called "phenomenal."
Last Friday, the University of Texas and North Dakota State University both issued campus-wide alerts after threats that turned out to be unfounded.
FBI spokesman Jason Pack said Monday the federal agency is working with the "affected jurisdictions" as they probe their respective cases, as well as assessing whether there may be a link between them.
"The FBI is looking into the recent threatening calls to college campuses to see if they might be related," Pack said.
CNN's Rick Martin contributed to this report.