The officers were wearing plainclothes and driving on Broadway near 65th Street around 5:45 p.m. when they were fired upon, Det. Meghan Aguilar said.
"At this time, the officers believe they were the target of the gunfire," said Aguilar, cautioning that the investigation is in the preliminary stage. "There's going to be several thorough interviews of the officers. But right now they believe they were the target."
The officers returned fire, Aguilar said. Several suspects scattered, but police detained a number of people in connection with the shooting. Police are still looking for two suspects, she said.
Authorities said the officers suffered minor wounds and were treated at the scene.
It is unclear whether the vehicle the officers were driving in was marked or undercover, she said.
Police cordoned off several blocks around the intersection, which is near where police last summer shot and killed Ezell Ford Jr., a mentally ill man, sparking protests.
The LAPD's SWAT unit was on the scene Sunday evening. Dozens of officers — as well as some police dogs — moved block by block in an attempt to hunt down the people involved in the shooting.
"We have active search teams going through the neighborhood," Aguilar said. "We're asking the public to shelter in place and notify police if they see any unusual activity in their houses or yards."
Junior Moore, 54, said he was eating at Hercules Burgers at Broadway and Gage Avenue when the gunfire erupted.
"I heard like 20 shots, and then a bunch of police sirens," Moore said.
Priscilla Gutierrez, 17, who lives two blocks from where the shooting took place, said she was on her way home from dinner with her mother and sister when they saw police tape blocking off their street.
Police told them it would be up to an eight-hour wait before they could return home.
The family was among about 50 local residents clustered behind police tape at the Gage and Broadway intersection.
Neighbors snapped photos as dozens of police cars arrived and officers strapped on SWAT gear, holding long black rifles.
They also watched as three large, armored SWAT vehicles entered the search area.
Gutierrez, who moved to the neighborhood two weeks ago, said she had heard gunfire erupt in the blocks near her house multiple times since Friday.
"We've been hearing gunshots," she said. "We don't go outside."