L.A. shopping malls on alert over terror threat. (Hat tip: Ed Moran.)

LOS ANGELES - Westside residents were being asked to be on the lookout for unusual activities around local shopping malls after a terrorism task force reported an “uncorroborated” threat of a possible attack Thursday.

FBI spokesman Matt McLaughlin said that because the “reliability of the source is unknown” and exact details were “unsubstantiated,” officials decided that as the date drew nearer and “out of an abundance of caution” they would “enlist the public’s help.”

He added that seeking public help is done “in cases all the time” and that many threats not unlike this one have been picked up in recent years.

No specific shopping mall was named, but the warning indicated a mall near the Federal Building in West Los Angeles could be targeted.