A tiger escaped its main enclosure on Thursday at the Oklahoma City Zoo, leading the institution to issue a "code red" and to shelter some visitors inside buildings, USA Today said based on local media reports.

Lola, the 4-year-old female Sumatran tiger in question, never entered an area accessible to the public, however, zoo spokeswoman Tara Henson assured NewsOK.com.

No injuries were reported in the incident, and a veterinary team was able to tranquilize Lola within about 20 minutes and take her to the tiger holding building for further observation. The animal seemed to be doing well, Oklahoma City Zoo Executive Director Dwight Lawson said.

"She was contained at all times," Lawson said about the feline. "We responded with the 'code red' because we weren't sure how she was able to get out of her enclosure. But the important point is that the staff responded appropriately. Our priority is public safety," he explained.

In a statement, the zoo detailed that Lola had been spotted at about 1:40 p.m. in an enclosed space between two exhibits of the Cat Forest habitat; she was immobilized by just after 2 p.m., and normal operations resumed at 2:25 p.m., USA Today detailed.

Oklahoma City ABC affiliate KOCO-TV claimed that the tiger had attacked another large cat, but the zoo made no mention of any such incident in its statement, the newspaper noted.

Rob Vernon, a spokesman for the Association of Zoos and Aquariums, meanwhile, said that his accrediting organization would request a report on the incident.

"We were very glad to see everything resolved without incident to zoo personnel or the tiger," Vernon contended.

The International Union for Conservation of Nature in 2008 put Sumatran tigers on its list of critically endangered species, which means that they are only two levels below extinction. At the time, only some 500 of the animals remained, and that number continued to decline, the organization warned.

The feline, one of the smallest tiger subspecies, is native to the Indonesian island of Sumatra.