By Michael Levenson and Sandra E. Garcia | The New York Times

The bodies of two transgender women were found inside a charred car in Puerto Rico on Wednesday, outraging activists who said the killings were part of a disturbing history of violence against L.G.B.T.Q. people on the island.

Pedro Julio Serrano, a gay rights activist in Puerto Rico, said that four transgender people had been killed there in the last two months. In the past 15 months, eight L.G.B.T.Q. people have been killed in Puerto Rico, he said. All of the deaths remain unsolved.

“This is an epidemic of violence, anti-L.G.B.T. violence that has resurfaced in Puerto Rico,” Mr. Serrano said Thursday. “We haven’t seen this type of violence in this quantity in a very long time — I would say 10 years.”

While the police were waiting for DNA results to release the names of the victims, they were identified by Mr. Serrano and other activists as Layla Peláez, 21, and Serena Angelique Velázquez, 32.

The women were friends who lived in New York City — Ms. Velázquez in Queens and Ms. Peláez in the Bronx — and had recently returned to Puerto Rico, according to family members and activists. They were planning to fly back to New York later this month.

The police have determined that the killings were homicides, but said they were waiting for autopsy results to determine how the women were killed.

Their remains were found after a person called 911 to report a burned car on a desolate road in Humacao, on Puerto Rico’s eastern coast, just before 5 a.m. on Wednesday, according to Capt. Teddy Morales, the chief of criminal investigations for the Puerto Rico Police Department in Humacao. Captain Morales said investigators were hoping to identify two men who partied with the women at one of their homes on Tuesday night.

Images of the men were captured on one of the women’s social media accounts, he said. He said investigators were also reviewing security camera footage from businesses in the area.

The investigation is in its early stages, Captain Morales said. He added that just because the women were transgender “doesn’t mean it was a hate crime.” “I can’t just say this is a hate crime from the scene,” he said. “We need to know who killed them, why did he kill, and what were the motivations to say this was a hate crime.”

Luz Melendez, 29, Ms. Peláez’s cousin, said Ms. Peláez was an easygoing young woman who had been raised by her grandmother and was just beginning to explore the world. On Wednesday, the grandmother recognized her granddaughter’s badly burned car on the news and called the police, Ms. Melendez said.

“In reality, we never thought something like this would happen,” Ms. Melendez said Thursday. “She didn’t have bad friends and she was never in the street. It caught us by surprise since she transitioned so easily and she didn’t ever have any issues.” Ms. Velázquez’s family could not immediately be reached.

Ms. Velázquez and Ms. Peláez were believed to be the seventh and eighth transgender or gender-nonconforming people to have been killed in the United States this year, according to the Human Rights Campaign.

“Serena and Layla, like us all, had family, dreams, hopes — and they did not deserve to die,” said Tori Cooper, the director for community engagement for the Transgender Justice Initiative. “Transgender and gender-nonconforming people, especially women of color, are too often the victims of a toxic mix of transphobia, racism and misogyny.”

In February, Alexa Negrón Luciano, a well-known figure on Puerto Rico social media who was transgender and homeless, was shot to death after a McDonald’s customer complained that Ms. Negrón had spied on her in the women’s room.

Ms. Negrón’s final moments — framed in the headlights of a car amid a cackle of laughter — were posted on social media, a fact that activists said underscored the impunity homophobic attackers feel when committing such crimes.

Last month, Yampi Méndez Arocho, a 19-year-old transgender man, was killed in Moca, P.R., according to the Human Rights Campaign.

Violence against gay people in Puerto Rico first gained wide attention in the 1980s, when a man called “Angel of the Bachelors” went on a killing spree, picking up gay men at bars and slaying them. But the police did not begin paying attention until a prominent journalist was stabbed to death in 1985, Mr. Serrano said.

The serial killer, Ángel Colón Maldonado, is serving a life sentence for three murders, but he has been suspected in 27 more cases. Fifteen years after his conviction, Puerto Rico legislators passed a hate crime bill, but prosecutors have rarely used it, Mr. Serrano said.

Mr. Serrano and other activists said they were concerned that the investigation into the killing of Ms. Velázquez and Ms. Peláez could be hampered by negligence and homophobia, which they said had plagued previous investigations of gay and transgender people killed in Puerto Rico.

“We are asking the police to thoroughly, immediately, and transparently investigate these vile and atrocious murders,” said Ivana Fred, an L.G.B.T.Q. activist in Puerto Rico. “Trans people deserve to live in peace, with equity and freedom.”