CONWAY, Ark. (KTHV) - Tense moments on the University of Central Arkansas campus in Conway after an evacuation Thursday morning.

"It was kind of scary at first because we didn't know what was going on and I am 8 months pregnant so we didn't know what to do, We just heard the fire alarms go off," said Jennifer Harrell, a UCA employee.

Campus officials said they received a call at 10:30 Thursday morning of a medical situation.

"MEMS was on the scene as well as Conway Fire Department and at that time Conway Fire Department began to do an extensive search of the building to try to ascertain the source of a mechanical air quality issue," said Arch Jones with UCA.

Jones said the origin of the gas is still unknown. He said 11 people were taken to a hospital for non-life threatening injuries.

Student Teresa McGarity said four students from her classroom experienced symptoms.

"We found out we had a total of four people that were just, they looked a little pale, and one of them said they were a little dizzy and couldn't even stand up. At that point they (school officials) thought maybe it could have been carbon monoxide poison and had everybody evacuate the building," said McGarity.

Jones said contracted air quality specialist were called to investigate. He said classes were canceled Thursday, but will resume Friday at a location to be determined.