Japanese Prime Minister Fumio Kishida said on Friday that Shinzo Abe is currently in "very grave condition" after being shot.

He condemned the shooting in the western city of Nara during the campaign for Sunday's upper house election as an unacceptable attack and prayed Abe would survive the attack.

"Currently doctors are doing everything they can, at this moment. I am hoping and praying that former prime minister Abe will survive this," Kishida said on Friday. 

"I am not aware of the motives and background behind this attack, but this attack is an act of brutality that happened during the elections – the very foundation of our democracy – and is absolutely unforgivable," he continued.