SWAT teams swarmed on an LA apartment complex on Sunday afternoon, following reports of possible shots fired on a street where a large caravan of Trump supporters was passing through.

A woman driving past the caravan in Woodland Hills said she heard what sounded like gunshots around 11:30am local time and then noticed her tire was flat after being damaged by a projectile, possibly a bullet, LAPD said. 

Another witness told police that they had seen a person with a firearm stood on the balcony of a nearby apartment building in the 20600 block of Ventura Boulevard.

Police say they later obtained a photo of a man holding a rifle on a balcony of the same apartment building. The kind of rifle he was holding wasn't specified.

Tactical teams attempted to draw the alleged shooter and two others out from the apartment block at around 3:30pm after they reportedly barricaded themselves inside.

However, when police entered the unit at 4pm nobody was inside. Officers had launched a chemical irritant into the property to try and flush any occupants out, police said.

Officers locked down the building and evacuated nearby units, LAPD said. Detectives remain at the scene collecting evidence to help locate the suspects.

Only one of the three suspects is being sought as a potential shooter. The other two individuals were reportedly present inside the unit when the incident was reported.