After a bomb threat shut down the campus of the University of Texas at Austin Friday mornng, the school began allowing students back onto campus and into buildings later in the day.

The campus was evacuated following a call by a man who claimed to have placed bombs around campus. The man also said he was associated with al Qaeda.

The call came in at 9:35 a.m. EDT, and the unidentified man claimed the bombs would go off in less than two hours. The man reportedly had an unspecified Middle Eastern accent.

"He said he was associated with al Qaeda and said the bombs would go off in about 90 minutes," UT Austin representative Gary Susswein told Reuters.

Immediately upon receiving the call, university officials ordered the school's 51,000 students and its 24,000 faculty and staff members as far from campus as possible as the school was searched for any potentially dangerous materials.

The school sent out an emergency report on its website reading, "Immediately evacuate all buildings and get as far away as possible. More information to come."

After the campus was searched, UT Austin President Bill Powers declared around 1 p.m. EDT he was "extremely confident that the campus is safe" and allowed students to enter school buildings once again.

While students are allowed back onto campus, all classes for the day remain canceled.

Two other schools, North Dakota State University and Valparaiso University in Indiana, also issued security warnings Friday.

North Dakota State received a similar bomb threat not long after UT Austin received its own. The North Dakota university took similar measures, asking students to leave campus and searching the school for dangerous materials. Students are also allowed back on North Dakota State campus.

No link between the two threats has been found.

Valparaiso University sent out a warning to students Friday regarding an "unspecified threat."

The warning read: "An unspecific threat to campus was made through a graffiti message alluding to dangerous and criminal activity alleged to be carried out during the chapel break period on Friday. The broad threat provided no details with respect to location or type."