With two rapes reported in Fairmount Park in the last two weeks, police yesterday asked women not to go jogging alone.

"We encourage people to use the park areas," said Capt. John Darby of the Special Victims Unit. "But we're asking folks to use a buddy system."

Darby said there was no evidence linking Sunday's rape to an attack on Aug. 11, or to the so-called Fairmount Park rapist who attacked four women in city parks between 2003 and 2007. That person has never been caught.

Yesterday's warning came after a 21-year-old woman told police she was raped about 7:30 a.m. Sunday on the 3800 block of Edgely Drive, near the East Park Reservoir.

The woman, who police said grew up in the area but does not live here, left a friend's house on the 3200 block of York Street and was headed to the park for a jog when she heard a man call to her from behind, Darby said, as though he knew her.

The woman turned, saw that she did not recognize the man, and continued into the park. The man apparently followed her, Darby said, then grabbed her from behind, forced her into a wooded area off the path, and assaulted her. Afterward, he fled, and the woman went to a friend's house to call the police.

The man was described as black and in his 40s or 50s. He had close-cropped salt and pepper hair and a beard and moustache. He stands 5-feet-6 to 5-feet-8 and he has a medium build. He was wearing a blue shirt and jeans shorts, police said.

Police do not think he is the man responsible for the Aug. 11 rape of a jogger. Darby said the circumstances were different.

During that attack, a 34-year-old woman preparing to go for a jog was raped near Forbidden Drive and Bells Mill Road. Police have had few leads in that case; the woman has been unable to describe her attacker, police said, other than that he was wearing brown work boots, dirty jeans, and white garden-type gloves.

"We're kind of stymied right now in terms of a composite drawing," Darby said.

Until December, the more-than-9,000-acre park was patrolled by officers in the 92d Police District. Budget problems led Police Commissioner Charles H. Ramsey to disband the 92d, and since then policing has fallen to the 14th, 16th and 19th Districts, which border the park.

Philadelphia Lt. Frank Vanore said officers are assigned to patrol areas of the park on a regular basis. But some remote areas aren't accessible by cars, and other spots are dead zones for cell phone coverage.

Councilman Curtis Jones Jr., whose Fourth District includes large sections of the park, said the rapes raised the question of whether the park was better served by one police district familiar with the park or a combination of districts "that are getting to know the park."

Jones said he would follow up with Ramsey and Parks and Recreation Commissioner Michael DiBerardinis to determine whether there was an increase in crime in the park following the dissolution of the 92d District.

Police beefed up their presence in areas of the park after the Aug. 11 rape, and Vanore said officers also use dirt bikes to patrol far-flung sections. But in a city grappling with gun violence, drug wars and hundreds of homicides each year, officers in nearby districts can't always make it a top priority to cover the vast expanses of Fairmount Park.

In addition to running with a partner, Darby advised joggers to exercise during daylight hours when possible, and not to use earphones or anything that might interfere with hearing.

"It's important to be as aware of your surroundings as possible," he said. "Those are good suggestions no matter where you are."

The Aug. 11 attack took place two years to the day from the last known assault by the Fairmount Park rapist in a city park.

All of his victims were alone when he attacked them.

On July 13, 2003, he raped and strangled Rebecca Park, 30, a fourth-year medical student at the Philadelphia College of Osteopathic Medicine. Her battered body was found in a shallow grave covered with leaves about 30 feet from a trail near Conshohocken Avenue.

After raping two other women that year, the attacker disappeared for four years, until his DNA was linked to the rape of a 29-year-old woman in Pennypack Park in Northeast Philadelphia in 2007.

Police have described that rapist as muscular and dark-complected, with a short jawline, goatee, and bushy eyebrows. One victim described him as Latino, and said he appeared to be in his mid-20s. In one of the 2003 attacks, police said the rapist told a victim that he had siblings in Puerto Rico.