A heavily armed man arrested in Southern California has told US police he was in the area for West Hollywood's huge gay pride parade.
Los Angeles Mayor Eric Garcetti announced the arrest in Santa Monica while he was attending the LA Pride event.
A police source said guns and explosive materials had been found in the suspect's vehicle.
Police in Santa Monica would not immediately confirm the incident, but an afternoon news conference has been planned to discuss the arrest.
Television images showed police searching a white car parked on a residential street in the seaside city west of Los Angeles.
Los Angeles county sheriff's officials said the suspect told police that he was going to the pride parade to look for a friend. Authorities are now looking for that individual.
Santa Monica Police spokesman Saul Rodriguez said detectives are "not aware of what the suspect's intentions were at this point".
Neighbours called police after the man was spotted knocking on doors and "loitering in the area," Mr Rodriguez said.
Authorities do not know of any connection between the gay nightclub shooting in Orlando, Florida, and the Santa Monica arrest.
FBI spokeswoman Laura Eimiller said the agency is assisting the Santa Monica Police Department with the arrest of an individual, but would not supply any more details.
Tens of thousands of people have gathered in West Hollywood for the annual LA Pride.
Los Angeles County sheriff's officials say they are assisting with the investigation and there is no immediate threat.
Mr Garcetti said the pride event would continue in memory of the victims in Orlando.
"This march goes on - we go on - in the face of hate," he said.
Man arrested with weapons in California says was headed to gay pride event: L.A. Times https://t.co/cicdTtMZOF— Reuters U.S. News (@ReutersUS) June 12, 2016