4 officers shot in 2 separate attacks in Los Angeles

Four officers were shot in two separate attacks on Los Angeles law enforcement, leading to a manhunt in one case and a SWAT response to a barricaded suspect in the other.

In the first shooting, a black-clad gunman ambushed two undercover detectives returning to a police station early Tuesday.

Police Chief Charlie Beck described the shooting as an attempted assassination and mobilized a huge search involving helicopters, dogs and about 200 officers. The officers' wounds didn't prevent them from aiding the hunt for the attacker. Police still had not found the suspect early Wednesday.

Police initially cordoned off 25 square blocks of the Mid-City area of Los Angeles, leaving thousands of residents stranded in homes and forcing drivers to find detours for their morning commutes.

Later in the day, the search focused on a neighborhood just south of the LAPD's Wilshire substation, where the attack occurred.

At least 10 people were detained for questioning and released. Police also planned to look at surveillance video from homes and businesses.

One officer suffered a minor wound to the back of his head, either from a bullet graze or debris from the damaged car, officials said. The other had an injury to the back of his hand.

Across town Tuesday evening a police officer aiding in a probation check near South Los Angeles was shot in the face and the gunman barricaded himself inside a home.

The officer was hospitalized in stable condition Tuesday night and will require surgery, according to Los Angeles Police Cmdr. Andrew Smith. Television footage from the scene showed the victim awake and sitting up as he was loaded into an ambulance following the shooting on 117th Street in the Willowbrook area.

A probation officer suffered a minor graze wound to his leg. He was treated at the scene.

The two officers were carrying out a search of the house when they encountered the gunman, who opened fire, Smith said.

At least five officers exchanged gunfire with the suspect.

The officers were part of a unit conducting a parole-probation search of the home in an area patrolled by the LA County Sheriff's Department, the Los Angeles Times said.

Dozens of police officers including a SWAT team with snipers surrounded the home. Negotiators were talking to the gunman. Several surrounding homes were evacuated.

Officials said the two incidents did not appear to be connected.