Women from Japan’s island chain of Okinawa have demanded an apology from outspoken Osaka Mayor Toru Hashimoto, who defended the role of wartime sex slaves as “necessary”.

Twenty-five women’s groups in Okinawa said they “strongly protest” against Hashimoto’s remarks, reports AFP.

Okinawa “still sits in the midst of unhealed scars from war and daily violence imposed by the military,” a joint statement from the women’s groups said.

“Regardless of whether it is war-time or not, a view to use women as a tool to let out sexual frustration is intolerable,” Masako Ishimine, a senior member of a local women’s body, was quoted by the Okinawa Times as saying.

The remarks also drew criticism from South Korea and China, which described it as Japan’s “anachronistic” thinking of history.

Rechilda Extremadura, the executive director of Philippine advocacy group Lila Pilipina, whose 104 members were “comfort women” slammed Hashimoto’s comments as “callous”.

“No country has the right to violate women and make us victims so they can be fodder for war,” she said. “Someone in his position should be more responsible with his remarks”.