Norway is mourning the saboteur Joachim Rønneberg, who led a five-man team that daringly blew up a factory producing heavy water, depriving Nazi Germany of a key ingredient it could have used to make nuclear weapons.

The prime minister, Erna Solberg, said Rønneberg, who died on Sunday at 99, was “one of our finest resistance fighters” whose “courage contributed to what has been referred to as the most successful sabotage campaign” in Norway.

Rønneberg, then 23, was recruited by the Special Operations Executive, or SOE — Britain’s wartime intelligence gathering and sabotage unit — to destroy parts of the heavily guarded plant in Telemark, southern Norway, in a raid in February 1943.

In a 2014 Norwegian documentary coinciding with his 95th birthday, Rønneberg said the daring operation went “like a dream” — a reference to the fact that not a single shot was fired. Parachuting on to snow-covered mountains, the group was joined by a handful of other commandos before skiing to their destination. They then penetrated the factory to blow up its production line.

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Rønneberg said he made a last-minute decision to cut the length of his fuse from several minutes to seconds, ensuring that the explosion would take place but making it more difficult to escape. The group skied hundreds of miles across the mountains to escape and Rønneberg, wearing a British uniform, ended up in neutral Sweden.

Operation Gunnerside has been recounted in books, documentaries, films and TV series, including The Heroes of Telemark (1965), starring Kirk Douglas and Richard Harris.

“We must not forget what he stood for and has passed on to us,” said Eva Vinje Aurdal, the mayor of his hometown of Ålesund, 235 miles northwest of the capital, Oslo.

The town ordered flags to fly at half mast on Monday and flowers were laid at the foot of a sculpture of Rønneberg, showing him in a uniform, walking up a rocky path. Inaugurated in 2014 by Rønneberg, the granite monument carries the names of all the men who took part in the second world war raid.