Operation AS-1

'AS-1' was a Japanese naval sweep against US submarines in the waters off China and Formosa (20 February/17 March 1945).

Headed by the light cruiser Kashima, the Japanese force was provided by the 1st Escort Fleet and included the escort vessels Mikura, CD-2, CD-33 and CD-34, which departed Shanghai for Tinghai in readiness for an undertaking scheduled to last 20 days. The escort vessel Yashiro was to join the 'AS-1' force for operations off Zhoushan once her damage repairs had been completed.

The ships were ordered to maintain constant formation and were to be supported by the aircraft of one squadron operating from a base in the northern part of Formosa.

Further support for 'AS-1' was provided by the 5,700-ton fast troop transport (ex-light cruiser) Kitakami.

There followed two similar undertakings designated as 'AS-2' and 'AS-3'.