A young mountain lion wandered into an empty high school classroom in northern California on Wednesday and crouched under a desk, where the cat was safely confined as wildlife officials puzzled over how best to remove the animal, authorities said.

The juvenile cougar, weighing only about 40 pounds (18 kg), walked into the school as custodial staff were opening up the building before classes started, and neither the animal nor any humans were hurt in the incident, according to San Mateo County Sheriff's Office spokesperson Javier Acosta.

The unusual invasion occurred shortly before 8:30 a.m. in the town of Pescadero, a small coastal ranching and farming community near a wildlife refuge about 45 miles (72 km) south of San Francisco.

"The mountain lion very casually walked through campus and went into the classroom and hunkered down under a desk," Acosta told Reuters by telephone. A custodian then closed the door to the room, usually used for English classes, to keep the animal isolated inside.

Although no students had arrived yet, school officials decided to go ahead with classes, with pupils kept away from the puma-occupied room while state game personnel decided how to proceed, Acosta said.

"They've been on property since about 9:30 a.m., formulating a plan to safely and humanely remove the mountain lion from the classroom and return it to its natural habitat," Acosta said.

Closer preliminary observation showed that the cougar appeared to be somewhat emaciated, leading biologists on the scene to call for a veterinarian to examine the animal, said Ken Paglia, spokesperson for the California Fish and Wildlife Department.

If the puma, believed to be six months to a year old but of unknown gender, was found to be malnourished or otherwise unhealthy, it might be taken in for treatment before being released to the wild, Paglia said.

Mountain lion sightings are not uncommon in San Mateo County, often involving young males that apparently wander into populated areas while seeking to stake out their own territories, according to Paglia.

In any case, Wednesday's incident is likely to mark a memorable highlight for Pescadero High students in their last week of classes for the academic year.