Japanese organization Nihon Hidankyo, a grassroots movement of atomic bomb survivors from Hiroshima and Nagasaki, also known as Hibakusha, won the Nobel Peace Prize on Friday.

“Hibakusha is receiving the Peace Prize 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,” the Norwegian Nobel Committee said in its citation.

Witnesses to the only two nuclear bombs ever to be used in conflict have dedicated their lives to the struggle for a nuclear-free world.

“The Hibakusha help us to describe the indescribable, to think the unthinkable, and to somehow grasp the incomprehensible pain and suffering caused by nuclear weapons,” the committee said.

The Norwegian Nobel Committee has regularly put focus on the issue of nuclear weapons, most recently with its award to the ICAN, the International Campaign to Abolish Nuclear Weapons, who won the award in 2017.

The Nobel Peace Prize, worth 11 million Swedish crowns, or about $1 million, is due to be presented in Oslo on Dec. 10, the anniversary of the death of Swedish industrialist Alfred Nobel, who founded the awards in his 1895 will.

This is a developing story