A Los Angeles Police Department patrol car was fired on in an “unprovoked attack” Sunday night that put police officers around the city on tactical alert.

The shooting took place late Sunday in a neighborhood in South Los Angeles as two officers were responding to an unrelated radio call. Neither officer was hurt in the incident.

“A couple of officers were rolling down the street when they observed the muzzle of a rifle firing in their direction,” LAPD Sgt. James Shray told MyFox LA. “They responded to the muzzle flash.”

LAPD spokeswoman Officer Nuria Venegas told The Associated Press on Monday that one man was under arrest and a second suspect was being sought.

One of the officers returned fire at two suspects. The officers nabbed one of the suspects and recovered the rifle. 

LAPD Capt. Lillian Carranza told KTLA-TV that several rounds were fired at the patrol car.

“This was a completely unprovoked attack,” she said.

Dozens of police officers from around the city rushed to the area of the shooting to search for the second suspect, warning nearby residents to stay in their homes. The search involving 60 officers, a SWAT team and K-9 units was called off around 6 a.m. local time after the suspect could not be found.

Police did not say if they had determined a motive for the shooting, which follows weeks of protests in California and across the country against police killings of unarmed black men in Missouri and New York.

"Obviously, with what happened in New York and what we know is the sentiment right now nationwide, in the mornings or in the evenings when you put on your uniform, you're very much aware that there are some currents of anger toward police," Detective Meghan Aguilar told KABC-TV. "We're aware that we could be a target for individuals that are angry at law enforcement right now."

The New York gunman ambushed the officers and then killed himself after posting threats online, including references to the fatal shooting of 18-year-old Michael Brown in Ferguson, Missouri, and the chokehold death of Eric Garner in New York City. Both were killed by white officers.

Deputy Chief Bob Green told KNBC-TV at the scene of the Los Angeles shooting that "based on what's going on in the national picture, tensions are very high, that's not what we need. Whether or not this is related to that — too early to tell."

The Associated Press contributed to this report.