Japanese aircraft and ships causing panic along American Pacific coast line according to the U.S. Joint Intelligence Committee. Daily summary dated 12 December 1941

An item referred to RDF bearings which indicated the presence of a Japanese unit on the position 38-48 North latitude and 132-45 West longitude 500 miles West North West of San Francisco, USA. The unit stayed stationary for 2 hours. Air reconnaisance flights were fruitless. Suspicious activities of undentifies aircraft and ships resulted in a blackout between Bakersfield and San Diego. Armed Japanese fishing boats were reported putting in along the lower Californian (Mexican) coast.

Source

Map Room Papers (Roosevelt Administration) mr0422a. U.S. Joint Intelligence Committee. Daily summary No. 2 Dated 12 December 1941.