LOS ANGELES -- A mountain lion attacked and severely injured a bicyclist in an Orange County park and may have killed a man whose body was found nearby, authorities said.

The 2-year-old male cat, which weighed about 110 pounds, was later shot and killed, and its body was taken to a laboratory for testing, said Steve Martarano, a spokesman for the California Fish and Game Department.

Anne Hjelle had been riding with a friend in Whiting Ranch Wilderness Park shortly before dusk Thursday when the mountain lion attacked her, said Orange County Fire Capt. Stephen Miller.

The lion pounced on the 30-year-old's back, grabbed her by her head and began dragging her, said her friend, Debbie Nichols. Nichols said she screamed for help and grabbed Hjelle's legs in a struggle to free her.

"He dragged us down ... about 100 yards into the brush and I just kept screaming," Nichols said. "This guy would not let go. He had a hold of her face."

Other cyclists in the area threw rocks at the animal until it fled.

Hjelle was airlifted to Mission Hospital, where her condition was upgraded to serious early Friday, a nursing supervisor said. She had been listed as critical.

After the attack, the body of an unidentified man in his 30s was found at the top of a trail near a bicycle. Authorities weren't sure how long he had been there and couldn't confirm if the man was killed by the mountain lion, but Miller said, "it's pretty obvious that an animal was involved." An autopsy was planned Friday.

Authorities said a second mountain lion in the area was hit by a car and killed late Thursday and would also be tested.

Including Thursday's incident, there have been 13 mountain lion attacks on humans in California over the past 114 years, five of them fatal, said Doug Updike, a biologist with the state Fish and Game Department.

Last September, game wardens shot and wounded an aggressive mountain lion spotted near an equestrian center in San Juan Capistrano. The lion was later found and killed, state officials said.

In 1986, 5-year-old Laura Small was attacked while looking for tadpoles with her mother in Ronald W. Caspers Wilderness Park in Orange County. The girl's skull was partially crushed and she was left blind in one eye and paralyzed on her right side.

A 6-year-old boy was mauled in the same park a few months later. County supervisors closed most of the park to children for nearly a decade afterward.

Updike estimates there are between 4,000 and 6,000 adult lions roaming the Golden State, with usually five to seven mountain lions per 100 square miles. State law prohibits hunting or killing them.