The department shared video of the shooting in a Twitter post showing a person open fire through the passenger-side window of the patrol vehicle.
The officers were sitting in their patrol auto when a gunman walked up to the vehicle and opened fire "without warning or provocation".
"They are both critically injured, multiple gunshot wounds".
According to officials, both were rushed to the hospital and are undergoing surgery.
The wounded deputies were able to radio for help, he said.
The two deputies, a male and female officer with the Transit Services Bureau, were shot at the Compton PAX station.
"They are both still fighting for their lives, so please keep them in your thoughts and prayers", LA Sheriff's wrote on social media.
Congress Leader Adhir Chowdhury Goofs Up By Addressing Rhea Chakraborty As 'Mrs'
In her bail plea, however, the 28-year-old actor has said that she was "coerced" into making incriminating confessions. Sources said the NCB did not want to take Ms Chakraborty into custody because it could "weaken" her confession.
Authorities were searching for a suspect or suspects immediately following the incident.
Sheriff Alex Villanueva said at a late-night news conference that the two graduated from the sheriff's training academy about 14 months ago.
"This is just a sober reminder it's a risky job". "And our job does not get any easier because people don't like law enforcement", he added, referencing the nationwide protests against police violence that have been taking place since May, following the police killing of George Floyd. "It dismays me at the same time", he said.
The FBI Los Angeles Field Office is offering resources to assist with the response to the shooting.
President Donald Trump tweeted that whoever shot the deputies are, "Animals that must be hit hard!".
US Rep. Adam Schiff tweeted he was praying for the two deputies.