In 939, Sumitomo ordered his subordinate FUJIWARA no Fumimoto to attack two members of Kokushi (provincial governor) of the Bizen and Harima provinces (Bizen no suke [Assistant Governor of Bizen Province]: FUJIWARA no Takaiko, and Harima no suke [Assistant governor of Harima Province]: Koremoto SHIMADA) at the Sukieki in Settsu Province, and captured them.
天慶2年（939年）には純友は部下の藤原文元に摂津国須岐駅にて備前国・播磨国の国司（備前介：藤原子高、播磨介：島田惟幹）を襲撃させ、これを捕らえた。