Hiroshima marks atomic bombing anniversary amid fears of a new nuclear arms race

Bells tolled in Hiroshima on Saturday as the city marked the 77th anniversary of the world's first atomic bombing, with officials — including the United Nations Secretary General — warning of a new arms race following Russia's invasion of Ukraine.

Russia invaded Ukraine on Feb. 24; shortly after the start of the invasion, Russian President Vladimir Putin obliquely raised the possibility of a nuclear strike. The conflict has also heightened concerns about the safety of Ukraine's nuclear plants.

U.N. Secretary General Antonio Guterres joined the thousands packed into Hiroshima's Peace Park, at the center of the city, to mark the anniversary of the bombing that killed 140,000 in 1945. It is only the second time a U.N. Secretary General has taken part in the annual ceremony.

"Nuclear weapons are nonsense. They guarantee no safety — only death and destruction," Guterres said.

"Three quarters of a century later, we must ask what we've learned from the mushroom cloud that swelled above this city in 1945."

Guterres sidestepped a direct mention of Russia, which calls its invasion of Ukraine a "special military operation."

Hiroshima mayor Kazumi Matsui, whose city did not invite the Russian ambassador to the ceremony this year, was more pointed and critical of Moscow's military actions in Ukraine.

"In invading Ukraine, the Russian leader, elected to protect the lives and property of his people, is using them as instruments of war, stealing the lives and livelihoods of civilians in a different country," Matsui said.

"Around the world, the notion that peace depends on nuclear deterrence gains momentum," the mayor added.

"These errors betray humanity's determination, born of our experiences of war, to achieve a peaceful world free from nuclear weapons. To accept the status quo and abandon the ideal of peace maintained without military force is to threaten the very survival of the human race."

Russia's ambassador to Japan, Mikhail Galuzin, had offered flowers at a memorial stone in the park on Thursday, and told reporters his nation would never use nuclear weapons.

At 8:15 a.m. on Aug. 6, 1945, the U.S. B-29 warplane Enola Gay dropped a bomb nicknamed "Little Boy" and obliterated the city, with an estimated population of 350,000. Thousands more died later from injuries and radiation-related illnesses.

On Saturday, as cicadas shrilled in the heavy summer air, the Peace Bell sounded and the crowd, including Japan's Prime Minister Fumio Kishida, who is from Hiroshima, observed a moment of silence at the exact time the bomb exploded.

Prime Minister Kishida, who has chosen Hiroshima as the site of next year's Group of Seven summit, called on the world to abandon nuclear weapons.