China. (Japanese Post Office in China). 1906. Picture post card of 'tanjong Katong, Singapore' addressed to Tientsin, China bearing Japanese Post Office SG 3a, 1s pale-brown (on reverse) and SG 6a, 2s green tied by TANGKU/ I.J.P.O. date stamp '2nd Dec 06', and Tientsin arrival '3/12', struck twice.
Tangku is a scarce Japanese Post Office, not often seen.