The FBI warned police departments in California about the possibility of an Iranian drone attack on the US West Coast, according to an alert sent to law enforcement agencies.

According to the alert, Iran had allegedly considered carrying out a surprise attack using unmanned aerial vehicles launched from an unidentified vessel off the US coastline, The Caspian Post reports, citing ABC News.

The potential targets were said to be unspecified locations in California, in the event that the United States conducted strikes against Iran.

“We have no additional information on the timing, method, target, or perpetrators of this alleged attack,” the alert said, according to ABC News.

The warning was distributed to law enforcement agencies at the end of February, the report added.