"The San Diego Police Department is aware of [the] recent post on Craigslist [which] has since been removed. We are investigating collaboratively with our law enforcement partners," Zimmerman told Fox News.
She added that San Diego police have not detected any credible dangers so far.
On Sunday morning, 29-year-old Omar Mateen opened fire in the gay nightclub Pulse in Orlando, killing 49 people and injuring 53 others. The attack is the deadliest mass shooting in the history of the United States.