(CNN) -- Power struggles between drug gangs have led to a surge in homicides in Puerto Rico this year, local police and the FBI told CNN.
Police statistics show the number of homicides so far this year in the U.S. island commonwealth is 16% higher than last year's figure for the same time period -- an increase authorities attribute to drug violence.
"We believe what may be happening here is that struggle for power or the take over of power at certain drug points," said Harry Rodriguez, a spokesman for the FBI in San Juan, Puerto Rico.
There have been 526 homicides so far this year, compared to 452 during the same period in 2010, Puerto Rico Police Agent Hilda Rivera said.
The surge in violence has led to an upswing of fear among residents, including members of Puerto Rico's lesbian, gay, bisexual and transgender community, who say police are not doing enough to protect them.
After three openly gay people were killed earlier this month in a one-week period, the Washington-based National Gay and Lesbian Task Force decried what it called an "epidemic of anti-LGBT violence" in Puerto Rico
In an interview with CNN, a spokeswoman for the Puerto Rican police department denounced any speculation that the crimes had anything to do with the sexual orientation of the victims.
"They were part of the rising crime here. They were not targeted for being homosexual. I just don't think there is a connection," Rivera told CNN.
Of the more than 500 murders on the island in 2011, five of the victims were gay, she said.
Authorities said they suspected drug gangs were behind the slaying of four men who were shot in Rio Piedras Saturday. Three of the victims had criminal records related to drug trafficking, police said.
"This was a planned attack. The victims did not have a chance to get away. At this moment we have no suspects," Commander Orlando Melendez, Supervisor of Criminal Investigations in Puerto Rico told CNN affiliate WAPA-TV.
In the past few years, the FBI and other authorities have cracked down on drug-trafficking organizations in Puerto Rico, Rodriguez said.
And a Puerto Rican police initiative has dismantled some supply chains, he added.
Puerto Rican Gov. Luis Fortuno has pointed to the April conviction of Angel Ayala-Vazquez, alias "Angelo Milliones" -- who led Puerto Rico's most powerful drug trafficking organization -- as a sign that authorities were taking action.
Aware of the perception that the island has seen an increase in drug related homicides, Fortuno listed security among his campaign platform slogans in his re-election bid announced this week. He said he planned to transform the approach to fighting crime by "attacking its roots" and "breaking the major criminal organizations."
Fortuno also said he plans to implement new technology with "100% inspection of trucks entering the island" and centralized systems of DNA to catch criminals.
"We have arrested more than 5,960 criminals, dismantled more than 440 points of drugs and increased our conviction in drug related arrests to 90%," his campaign website said.
But Francheska Gonzalez, a transsexual who was the victim of a beating in April, said she was one of the survivors of a series of attacks against the LGBT community on the island. Police must do more to protect residents, she said.
"The aggressors continue to be on the streets," she said.
"I am scared for my life, for my health and for everything," said Gonzalez, adding that attackers hurled hate-slurs while beating her, breaking a vertebrae and rupturing one of her breast implants.
"This is about members of the Puerto Rican LGBT community feeling safe in their communities and being able to take care of the ones they love. ... This must stop now," Pedro Julio Serrano, communication manager of the Gay and Lesbian Task Force, said in a written statement.
This month the department announced it would be creating a new protocol system to "guarantee the civil rights and protections" of all the island's citizens.
"During this time we have the task of ensuring that members of the LGBT community are heard and addressed efficiently," Superintendent of Puerto Rico Police Department Jose Figueroa Sancha said in a statement.
CNN's Elwyn Lopez contributed to this report.