A shooting in the southern California city of El Monte left two police officers and a suspect dead, authorities said late on Tuesday, adding that the officers were shot in the line of duty while responding to a report of a possible stabbing.

"The El Monte Police Department responded to a possible stabbing at the Siesta Inn and officers immediately took gunfire upon arrival," police said in a statement.

"The city of El Monte is saddened and shocked by tonight's tragic shooting that killed two of our own police officers."

Gun violence in the United States has been under scrutiny after last month's massacres at an elementary school in Uvalde, Texas - which left 19 children and two teachers dead - and a supermarket in Buffalo, New York - which killed 10 people.

The mass shootings in Uvalde and Buffalo have prompted new efforts in the U.S. Congress to enact stricter federal gun control laws.

The two officers who were shot were taken to the LAC-USC Medical Center where they died from their injuries, authorities said. The Los Angeles County Sheriff's Department was probing the incident.

A suspect in the shooting, an unidentified man, was also killed during the exchange of gunfire, the Los Angeles County Sheriff's Department said.

The names of the officials were not released. Local media outlet KTLA said one of the officers was a 22-year veteran of the El Monte Police Department while the other had been a member of the police force for less than a year.