From NYPD Shield:

News agencies are reporting there was an explosion outside a synagogue in Santa Monica, California. There are no immediate reports of injuries and local police have not confirmed the cause of the explosion or if the temple was deliberately targeted. We will continue to monitor this event and will advise of any new information that has been confirmed by local authorities.

 Read more in the Los Angeles Times.

The Chabad of Santa Monica website reports:

In response to news reports of a pipe bomb in our facility. During morning services today the police department came to Chabad House in response to a report of an explosion. The men that were praying did not hear or feel anything. Rabbi Levitansky grabbed on of the new Torah scrolls so they can finish services. Which they did at the corner of 17th and S. Monica.