PHILADELPHIA – Two women from the United Kingdom flew into Philadelphia on Saturday looking to improve their physiques with buttocks-enhancement injections.

Only one survived.

The other died at a suburban Philadelphia hospital Monday, and Philadelphia homicide detectives are now seeking two women who provided the syringes and unknown drugs in a hotel room near the airport.

Their clients were part of a group of four women, all in their 20s, who arrived Saturday. The two who did not receive injections were on their way to a party in New York City, said Detective Lt. John Walker.

Late Tuesday, police confirmed that the dead woman was Claudia Adusei, 20, of London. Police said that the other woman told them the women thought they were being injected with silicone. The autopsy will show whether the substance was in fact silicone, police said.

Buttocks-enhancement injections, often involving silicone gel or liquid, are illegal but widely available. Dozens of women have reported injuries including infections, kidney impairment, and, in rare instances, death, according to federal health agencies.

Walker said the victim checked into a Hampton Inn and sometime over the weekend received the injections. She was taken to Mercy Fitzgerald Hospital at 1:30 a.m. Monday after complaining of chest pains and experiencing shortness of breath.

She died later that day. Fredric Hellman, Delaware County medical examiner, said a preliminary cause of death will not be released until the victim’s relatives are notified. The second woman, who received injections to her buttocks and hips, has not been hospitalized, police said.

Legitimate buttocks enhancements using silicone implants are relatively rare — about 5,000 were done throughout the nation last year. There is a large illegal underground market for the sale and injection of silicone.

“Silicone injections used to be done years ago to make breasts bigger … but that has not been done, legitimately, for 40 or 50 years,” said R. Barrett Noone, a Philadelphia area plastic surgeon who serves as executive director of the American Board of Plastic Surgery.