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

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

Last year, the prestigious prize went to imprisoned women’s rights campaigner Narges Mohammadi for her fight against the oppression of women in Iran.

The prize comes with a gold medal, a diploma and a prize sum of $1 million (913,000 euro).

The award will be presented at a formal ceremony in Oslo on December 10, the anniversary of the 1896 death of the prizes’ creator, Swedish inventor and philanthropist Alfred Nobel.

The Peace Prize is the only Nobel awarded in Oslo, with the other disciplines announced in Stockholm.

On Thursday, South Korean author Han Kang won the Nobel Prize in Literature for her work exploring the correspondence between mental and physical torment as well as historical events.

The Nobel season winds up Monday with the economics prize.