A reward of $20,000 was being offered for information that leads to the arrest of whoever has made more than three dozen unfounded bomb threats at Naval Base San Diego and nearby shipyards since November.
The Naval Criminal Investigative Service together with BAE Systems and NASSCO put up the money in an effort to halt the hoaxes, which have interrupted work and forced federal law enforcement agents off their regular investigations.
Two threats were made Friday at Pier 7 aboard the Barrio Logan-area installation.
Navy officials said messages have been found over the past nine months scrawled on a bulkhead inside a docked ship, inside portable toilets, a ship's stairway and plumbing pipe, among other places. A few threats were called in.
Anyone with information on the cases was asked to call the NCIS at (619) 556-1364 or (877) 579-3648. Tips can also be texted to 274637, with "NCIS" typed at the beginning of the text.