Authorities in Southern California went on a heightened state of alert after Monday's Boston Marathon bombing, beefing up security at LAX, Dodger Stadium and other venues where crowds congregate.
Law enforcement said they took the steps to reassure the public while guarding against the possibility of potential attacks related to or inspired by the Boston bombings that left at least three dead and dozens injured.
LAX, the target of the failed 1999 millennium bomb plot, immediately stepped up police patrols and employed additional bomb-sniffing dogs in and around terminals and parking areas.
"While there is no information to suggest that there is any nexus to the Los Angeles area, in an abundance of caution, Airport Police has increased its presence at LAX, LA/Ontario International and Van Nuys airports by deploying bomb-detection canines, additional patrol officers and security personnel," L.A. World Airports said in a statement.
Police focused their attention on protecting key infrastructure, sites where crowds gather or places of cultural or iconic significance, and urged the public to immediately report suspicious activity.
Los Angeles Mayor Antonio Villaraigosa said in a statement: "We are working closely with our law enforcement partners to monitor the situation and stand ready to aid Boston in any way possible. The LAPD and other public safety agencies will remain vigilant at all public and sporting events in Los Angeles."
To that end Police Chief Charlie Beck said Monday that his department will increase officer deployments at sporting events, beginning with the Dodgers-San Diego Padres baseball game Monday evening.
The LAPD had planned to increase the number of officers at the Dodgers-Padres game anyway, expecting it would draw more people after a brawl last week in San Diego left Dodgers pitcher Zack Greinke injured.
But the events in Boston led officials to also deploy bomb-squad personnel, dogs and other "precautions geared to preventing a similar event," Beck said.
Also stepping up security is this weekend's Toyota Grand Prix of Long Beach, which each year draws more than 170,000 spectators for racing Friday through Sunday.
The Los Angeles County Sheriff's Department said it too would have higher visibility.
"While the cause of the explosions this morning at the Boston Marathon are still under investigation, our vigilance has been raised," said Sheriff Lee Baca, noting that the bombing hit home for him as a law enforcement leader and as a long-distance runner.
While his deputies increased patrols in areas that attract crowds, including "government buildings, shopping centers, athletic events and public transit," Baca said such acts must not cut into the freedoms Americans enjoy.