Two FBI agents were shot dead and three were wounded on Tuesday while serving a search warrant on a suspect in a child pornography case in the southern US state of Florida, the FBI said.
The suspect is also dead, the Federal Bureau of Investigation said in a statement.
The FBI and media reports said the shooting took place around 6:00 am in Sunrise, Florida, when agents arrived to execute a search warrant at the suspect's home.
FBI Director Christopher Wray identified the two slain FBI special agents as Daniel Alfin and Laura Schwartzenberger.
"The FBI will always honor their ultimate sacrifice and will be forever grateful for their bravery," Wray said in a statement.
Two of the wounded agents were taken to hospital and are in stable condition, the FBI said. The third agent did not require hospitalization.
A law enforcement source told the Miami Herald that the suspect had shot and killed himself after barricading himself in his home for several hours.
The newspaper said the FBI agents had been seeking to seize the suspect's computer and other evidence in a child pornography case.
White House spokeswoman Jen Psaki said President Joe Biden had been briefed by Homeland Security officials about the shooting.
"This is obviously a terrible tragedy," Psaki said.
The two slain FBI agents were the first to be shot and killed in the line of duty since an agent was shot dead in Pittsburgh, Pennsylvania, in 2008, according to FBI records.