OSLO: The Nobel Peace Prize was on Friday awarded to the Japanese anti-nuclear group Nihon Hidankyo, a grassroots movement of atomic bomb survivors from Hiroshima and Nagasaki, also known as Hibakusha.

The group, founded in 1956, received the honour "for its efforts to achieve a world free of nuclear weapons and for demonstrating through witness testimony that nuclear weapons must never be used again," said Jorgen Watne Frydnes, the chair of the Norwegian Nobel Committee in Oslo.

The co-head of the group expressed surprise at winning the award.

"Never did I dream this could happen," Toshiyuki Mimaki told reporters in Tokyo with tears in his eyes.

The Nobel committee expressed alarm that the international "nuclear taboo" that developed in response to the atomic bomb attacks of August 1945 was "under pressure".

The war in Ukraine has recently heightened concerns about the risk of nuclear war, in particular with Russia's announcement that it plans to review its doctrine on the use of the atomic weapons.

"This year's prize is a prize that focuses on the necessity of upholding this nuclear taboo. And we all have a responsibility, particularly the nuclear powers," Frydnes told reporters.

Japan's Prime Minister Shigeru Ishiba said the award for Nihon Hidankyo was "extremely meaningful".

The committee noted that next year will mark 80 years since two American atomic bombs killed an estimated 120,000 inhabitants of Hiroshima and Nagasaki, and a comparable number later died of burn and radiation injuries.