Tokyo: Japan`s Prime Minister Shinzo Abe said Sunday the "credibility" of a video announcing the execution of a Japanese hostage by the Islamic State militant group was "high".
"We have been looking into its authenticity, but unfortunately at the moment we cannot help saying its credibility is high," he said on the public network NHK.
"Considering the unbearable pain and sorrow that his family must be feeling, I am speechless," he said.
"Such act of terrorism is outrageous and impermissible, it causes me nothing but strong indignation," he added. "I condemn it strongly and resolutely."
The government will continue analysing the images to fully confirm the authenticity of the video, Abe said.
The nearly three-minute recording, posted online Saturday, shows a still image of Kenji Goto holding an apparent photograph of Haruna Yukawa`s slain body, with an audio recording in which Goto spoke of the IS group`s demand for a prisoner exchange to guarantee his release.
It was not posted on any of the group`s official channels and it does not bear their black and white flag. The purported execution of Yukawa is also not shown.