Two jaguars at a zoo were in quarantine Monday after at least one of them attacked and critically injured an animal care worker.

The woman was attacked Sunday morning while working in the interior den area of the jaguar enclosure, the Catoctin Wildlife Preserve and Zoo said in a statement.

When she called for help, staff moved the animals from the interior den to the exterior exhibit area, the statement said. The woman was given first aid by staff and emergency medical technicians before being brought to Maryland Shock Trauma in Baltimore.

Zoo officials are investigating the attack. The zoo is in Thurmont, Maryland, about an hour outside Baltimore.

The worker suffered several bite wounds, according to Harold Domer, Frederick County Animal Control director. There was never any risk to anyone else, he said. The zoo is closed to the public for the season.

The attack occurred in an indoor area that has a steel door to the outside exhibit area.

Domer said the worker was attacked by a 13-year-old male jaguar weighing between 180 pounds and 200 pounds (80 to 90 kilograms). He said animal control workers did not know for sure if the second jaguar, a female, entered the indoor area or took part in the attack.

According to Domer, an inspection Monday showed the door "has several devices that allow the door to be locked." He called the safety precautions "extremely adequate." It was not clear how the male jaguar was able to pass through the door to the den.

The jaguar was current on its vaccinations, Domer said.

Calls and e-mail requests for details from zoo officials Monday were not immediately returned.

The woman's name has not been released. Domer said that, as of Monday, the 32-year-old woman's condition was critical, but stable. A hospital spokeswoman did not immediately return a call Monday.