Donald Trump says shooter of two Los Angeles County Sheriff's deputies should get death penalty if the officers die

The shooting, which happened a short distance from the Compton sheriff's station, sparked an anti-police protest outside the hospital where the deputies were being treated, as authorities continued to hunt for the attacker.

The deputies were both shot in the head while sitting in their patrol car at a train station and were able to radio for help, Sheriff Alex Villanueva said.

The 31-year-old female deputy and 24-year-old male deputy underwent surgery for multiple gunshot wounds on Saturday evening (local time).

Both graduated from the academy 14 months ago, the sheriff said.

The department has tweeted video of the shooting that shows a person firing a pistol through the passenger window of the patrol car.

"The gunman walked up on the deputies and opened fire without warning or provocation," the department stated.

Trump calls for death penalty if shooting proves fatal

The video sparked thousands of reactions, including from President Donald Trump, who responded: "Animals that must be hit hard!"

He also said that if the wounded officers died, the shooter should be given the death penalty after a fast trial.

Mr Villanueva, whose department has come under fire during recent protests over racial unrest, expressed frustration over anti-police sentiment as he urged people to pray for the deputies.

"It pisses me off. It dismays me at the same time," he said.

Protesters gathered outside the hospital where the injured deputies were being treated.

"To the protesters blocking the entrance & exit of the HOSPITAL EMERGENCY ROOM yelling 'We hope they die' referring to 2 LA Sheriff's ambushed today in #Compton: DO NOT BLOCK EMERGENCY ENTRIES & EXITS TO THE HOSPITAL," the sheriff's department tweeted.

"People's lives are at stake when ambulances can't get through."

A radio reporter who was near the protest scene was taken into custody, KABC-TV reported.

The sheriff's department later tweeted that the reporter interfered with the arrest of a male protester.

"The female adult, who was later identified as a member of the press, did not identify herself as press and later admitted she did not have proper press credentials on her person," the department stated.

After being released, Josie Huang, a reporter for radio station KPCC, tweeted that she had seen the statements from sheriff's officials and had "thoughts and videos to share soon after a little rest".

The executive editor of the station expressed outrage over the arrest and said Huang had appeared to be wearing credentials and had shouted her KPCC affiliation.