Conflicts raging around the world, including in Gaza, are heightening the possibility of a nuclear war, the winner of this year’s Nobel Peace Prize warned, renewing calls for the abolition of nuclear weapons.

Nihon Hidankyo, the grassroots group of Japanese atomic bomb survivors, won the prize on Friday for its “efforts to achieve a world free of nuclear weapons”.

On Saturday, Shigemitsu Tanaka, a survivor of the 1945 bombing of Nagasaki by the United States and co-leader of the group, said the “international situation is getting progressively worse, and now wars are being waged as countries threaten the use of nuclear weapons”.

“I fear that we as humankind are on the path to self-destruction. The only way to stop that is to abolish nuclear,” the resident of Nagasaki told reporters.

Nagasaki was the second Japanese city that was hit by a US nuclear bomb on August 9, 1945, killing at least 74,000 people. Three days earlier, the US bombing of Hiroshima had killed 140,000 people.

Hiroshima residents said on Saturday they hoped the world never forgets the bombings of 1945 – now more than ever.

Susumu Ogawa, 84, was five when the bomb all but obliterated Hiroshima 79 years ago, and many of his family members were among the tens of thousands killed.

“My mother, my aunt, my grandfather, and my grandmother all died,” Ogawa told the AFP news agency.

“All nuclear weapons in the world have to be abandoned,” Ogawa said. “We know the horror of nuclear weapons, because we know what happened in Hiroshima.”

What is happening now in the Middle East, with Israel’s wars in Gaza and Lebanon and escalating tensions with Iran, saddens him.

Russian President Vladimir Putin signalled in September that Moscow would consider responding with nuclear weapons if the US and its allies allow Ukraine to strike deep inside Russia with long-range Western missiles.

“Why do people fight each other?… Hurting each other won’t bring anything good,” Ogawa said.

On Saturday, Japanese demonstrators rallied in support of Palestinians in Gaza, at the preserved Atomic Bomb Dome in the Hiroshima Peace Memorial Park.

Toshiyuki Mimaki, the co-chief of the group and a survivor of the Hiroshima bombing, said on Friday that the situation for children in Gaza is similar to that of Japan at the end of World War II.

“In Gaza, bleeding children are being held [by their parents]. It’s like in Japan 80 years ago,” Mimaki told a news conference in Tokyo.

Nihon Hidankyo was formed in 1956, tasked with telling the stories of hibakusha, as the survivors are known, and pressing for a world without nuclear weapons.

With the average age among the roughly 105,000 hibakusha still alive now 85, it is vital that young people continue to be taught about what happened, residents said.

Visiting the Hiroshima memorial, Kiyoharu Bajo, 69, said he hoped the Nobel prize would help “further spread the experiences of atomic bomb survivors around the world” and persuade others to visit.

“I was born 10 years after the atom bomb was dropped, so there were many atom bomb survivors around me. I felt the incident as something familiar to me,” he said.

“But for the future, it will be an issue.”