Los Angeles law enforcement authorities were focusing extra patrols Monday on local airports, mosques and synagogues as a precaution after Osama Bin Laden was killed by U.S. forces Sunday.

Law enforcement sources said those locations were considered the most important potential targets in the short term but that other locations would likely be added.

Chief Charlie Beck said the Los Angeles Police Department plans to beef up police patrols at large public gatherings, such as upcoming Lakers playoff games at Staples Center.

Metro spokesman Marc Littman said security has been increased at L.A.'s public transit hubs with measures such as bomb-sniffing dogs at many stations, as well as more plainclothes officers and foot patrols.

Littman said there was also increased security on subway lines and in other public transit areas.

LAPD counter-terrorism officials are scheduled to talk with federal authorities Monday to discuss further measures that may be taken, Beck said. "We are doing everything within our ability to make sure people are as safe as they can be," Beck said in an interview with The Times.

Mayor Antonio Villaraigosa echoed the call of Beck, Los Angeles County Sheriff Lee Baca and other law enforcement officials for residents to be alert and to report suspicious activities.

"We must continue to be vigilant and remain on guard against those that still seek to harm us," the mayor said in a statement Sunday. "Although we will never forget the tragic events of 9/11 ... we recognize this significant milestone in the healing process of our nation and we thank all those across the country and around the world who are hard at work to keep us safe."

LAPD Deputy Chief Mike Downing, commanding officer of the Counter-Terrorism and Special Operations Bureau, said the LAPD has already begun patrols at some possible terrorism targets, including religious institutions.

"We are somewhat concerned about any retaliation because of [Bin Laden's] death," Downing said. "But with our partnerships and relationships that we've built over the last four or five years, we will stand with these communities to resist any attacks or hate incidents."

He urged anyone who sees unusual activity to contact the LAPD through iwatchla.org or through the (877) A-THREAT tip line.

Gina Marie Lindsey, executive director of Los Angeles World Airports, which operates Los Angeles International, Ontario International and Van Nuys airports, said all of the facilities were on heightened alert.

"We have our antenna out higher than normal," she said.

Lindsey would not elaborate on security measures or detail what types of new patrols might be used at LAX.

Baca has also said his department is on heightened alert and urged residents to be watchful for suspicious activity.