LOS ANGELES (CBSLA.com) — Security was ramped up on bus and rail lines in Southern California Friday in the wake of a rush-hour explosion on a London subway train that injured dozens of people.

Los Angeles police officials say after communicating with UK officials, they have determined there is no evidence of a nexus between the attack in London and Los Angeles.

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“As a precautionary measure, however, the LAPD will increase its presence on MTA rail and bus lines and ensure that major tourist venues see increased security measures,” LAPD officials said in a statement.

Police urged members of the community to be vigilant and report suspicious activity.

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Suspicious activity can be reported directly to the LAPD by downloading and using the iWatch app from the Apple or Android stores.

Tips can also be made anytime to (877) LAPD-247 (527-3247), or to Crime Stoppers at (800) 222-TIPS (8477).

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(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. City News Service contributed to this report.)