Evacuation orders were issued at a US University after a bomb threat was received on the campus, a month after similar warnings created panic at three institutions.

Officials at Texas A&M University ordered all students, faculty and staff to evacuate the campus.

The 'Code Maroon' was issued at 11:34 a m and officials asked everyone to evacuate campus by foot immediately.

"Do not use a vehicle. Classes have been cancelled," said a message.

Lt Allan Baron, Texas A&M police spokesman, said the threat was received via email and then the department was notified.

"We're encouraging people to follow emergency.tamu.edu which we will be updating on a regular basis as more information becomes available," he said.

Rhonda Seaton, College Station police spokeswoman, said the department is assisting with traffic and helping to evacuate the campus.

She said they are asking every one in the area to please leave the campus.

"I've been told traffic right now is just as bad as a game day," Seaton said.

Sophomore Romina Morgan said she was sitting outside eating with a friend when she got the Code Maroon text about 11:40 a m.

She said there was a lot of confusion among students as to where they were supposed to be evacuating to.

Texas A&M has more than 50,000 students, according to the school's website.

Last month, telephoned bomb threats at the University of Texas at Austin, as well as ones made to campuses in North Dakota and Ohio prompted tens of thousands of people to evacuate. However, no bombs were found at any of those campuses.