Two FBI agents have been killed and three others wounded while trying to serve a search warrant at a Florida home, an encounter that turned into one of the law enforcement agency’s bloodiest in decades.

As a team of officers tried to execute the court-ordered warrant involving violent crimes against children at the home in Sunrise, Florida, shots were fired at 6 am on Tuesday (local time), the FBI said.

The warrant sought evidence in connection with suspected possession of child pornography, the FBI Agents Association added.

Two of the wounded agents were in stable condition at a hospital, while the third did not require hospitalisation. The subject of the warrant, who was not identified, also died.

The man being investigated had apparently barricaded himself inside an apartment complex and was found dead, the New York Times reported, citing officials. It was unclear how he died, the newspaper said.

The scene near the home in Sunrise, just west of Fort Lauderdale and about 48 km north of Miami, was swarming with emergency and law enforcement vehicles from the FBI and police in Sunrise and surrounding jurisdictions.

White House press secretary Jen Psaki told reporters President Joe Biden had been briefed on the incident and would likely address it later on Tuesday.

FBI Director Christopher Wray identified the dead agents as Daniel Alfin and Laura Schwartzenberger and hailed them as heroes.

“Special Agent Alfin and Special Agent Schwartzenberger exemplified heroism today in defence of their country,” Wray said in a statement.

“The FBI will always honour their ultimate sacrifice and will be forever grateful for their bravery.”

The shooting deaths, which remain under investigation, were among the bloodiest episodes for the FBI.

In 1994, two agents were shot dead along with a police detective at the Washington DC police headquarters when a homicide suspect opened fire on them with an assault weapon, also wounding a third agent.

Another deadly encounter occurred in 1986, also in Florida, when two agents were killed and five others were wounded in a Miami shootout with two bank robbery suspects, the FBI said.

The last fatal shooting of an FBI agent on duty was on Nov. 19, 2008, which also unfolded during the execution of a warrant.

-AAP