Two universities, in Texas and in North Dakota, ordered the evacuation of their campuses on Friday after receiving bomb threats.

The first threat came at about 8:35 a.m. CDT Friday at the University of Texas, which ordered the Austin campus to be evacuated after receiving a threat from a man claiming to be from al-Qaida.

The second threat came about 90 minutes later at North Dakota State University in Fargo. There were no other details immediately available on that incident.

The Texas evacuation, at the largest campus in the UT system, came in response to a caller with a Middle Eastern accent, officials said.

“At 8:35 this morning, the university received a call from a male with a Middle Eastern accent claiming to have placed bombs all over campus. He said he was from al-Qaida and that these bombs would go off within 90 minutes,” Tara Doolittle, a university spokeswoman, told the Los Angeles Times.

The call was placed to Walter Webb Hall, she said, which houses a number of offices, including the campus visitor center. She said it was not clear who the caller was, from where he placed the call or why he contacted officials at that building.

Officials notified university President Bill Powers immediately after receiving the bomb threat, Doolittle said, “and it was decided to evacuate all the buildings on campus out of an abundance of caution.”

The evacuation order was issued at 9:30 a.m. via email and the campus website, following a university evacuation plan, she said. Building managers were also notified, and the evacuation proceeded without incident, she said.

At least 51,000 students are enrolled at the university, but it was unclear how many were on campus at the time of the evacuation, Doolittle said.

“Everyone’s left. People were very orderly when they filed out and have gone to nearby restaurants or back to their residences,” she said.

The 90-minute window came and went without incident, but campus police are continuing their investigation, officials said.

The evacuation was expected to last “until police deem the campus secure,” Doolittle said. She said she could not recall any other recent evacuations of the entire campus.

In a later Twitter message, officials said: “Buildings being checked/cleared. Stay away from buildings. No decision on afternoon classes/activities.”

Meanwhile, North Dakota State University officials issued what they called an “urgent security alert,” posted on the school’s website.

The alert came shortly before 10 a.m., with the school telling all employees and students to leave campus within half an hour because of a bomb threat. Students in residence halls have been told to walk to locations off campus.