Two police officers have been killed and a third left injured after a gunman allegedly ambushed them at a Bristol, Connecticut, home.

On Wednesday, Bristol police Sgt. Dustin DeMonte, 35, and officer Alex Hamzy, 34, were shot while responding to a 911 call reporting a possible domestic violence incident between two siblings, according to Connecticut State Police.

The state police said that the initial 911 report might have been a gimmick, saying in a statement that its investigation suggested the call had been placed in a “deliberate act to lure” officers to the home on Redstone Hill Road.

The injured officer, 26-year-old Alec Iurato, underwent surgery for a severe gunshot wound and was released from a Hartford hospital on Thursday morning.

The suspect, Nicholas Brutcher, was shot and died at the scene, the police said. The suspect’s brother was also shot and has been hospitalised in unknown conditions, according to police.

Connecticut Governor Ned Lamont called the slayings a “senseless tragedy” and ordered flags in Connecticut to be lowered to half-mast. 

“This is a devastating reminder of the dangers that police officers face every day to protect our families and neighbours from all kinds of situations. These officers are heroes,” Mr Lamont said.

According to data from the Federal Bureau of Investigation, as of September 27, 49 officers have been killed in the United States this year.