COMPTON, Calif. (NewsNation Now) — The Los Angeles County Sheriff’s Department on Sunday announced a $100,000 reward in the search for a man who shot and injured two deputies Saturday in an apparent ambush caught on video.

The U.S. Justice Department said on Twitter Sunday it would assist sheriff’s investigators with “all federal tools available.”

Los Angeles Mayor Eric Garcetti promised justice for the deputies injured.

“Of course, there’s an important conversation going on about policing in this country, but these are folks who put their lives on the line for us, and we will find justice for them,” Garcetti said on CNN Sunday.

The deputies were shot while sitting in their patrol car at a Metro rail station and were able to radio for help, Sheriff Alex Villanueva said. The shooting occurred in Compton Saturday at around 7 p.m. PT, NewsNation affiliate KTLA reported.

A 31-year-old female deputy and 24-year-old male deputy underwent surgery Saturday evening, Villanueva said in a late-night news conference. They remain in critical condition, authorities said.

Both deputies graduated from the academy 14 months ago, according to Villanueva.

“These are real people doing a tough job, and it just shows the dangers of the job — in the blink of an eye,” Villanueva said.

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 officers.

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

The department shared video of the shooting in a Twitter post showing a person open fire through the passenger-side window of the patrol car.

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

The video sparked thousands of reactions, including from President Donald Trump, who responded via Twitter, “Animals that must be hit hard!”

Protesters gathered outside the emergency room at 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.”

Capt. Kent Wegener said officers were blanketing the area in search of the suspect seen on the video opening fire with a pistol.

The video was taken with a fisheye lens, likely distorting the appearance of the shooter’s actual height and weight, Wegener said.

“We have a very, very generic description,” he said.

The Associated Press and NewsNation affiliate KTLA contributed to this report.