TOKYO: Kurdish authorities have detained a Japanese freelance journalist covering the fighting in Iraq, according to Japan's government and media reports.

Japanese government spokesman Yoshihide Suga said Tuesday that Japan was aware that Kosuke Tsuneoka was being detained by "government authorities of the Kurdish region."

Tsuneoka was reporting on the battle to recapture the city of Mosul from the Islamic State group, Japan's Kyodo News agency reported.

He is being held by Kurdish military forces known as the peshmerga, Kyodo said.

It's unclear why he was detained.

"We are still confirming details of his charges with local authorities," Suga said.

He added that the Japanese Embassy in Iraq was requesting access to Tsuneoka and calling for appropriate treatment of him while he is being investigated.

Iraqi forces and their Kurdish allies, Sunni tribesmen and Shiite militias have been converging on Mosul from all directions since Oct. 17, but progress has been uneven.