Hiroshima marks 70 years since atomic bomb

The Japanese city of Hiroshima today is commemorating the 70th anniversary of the first atomic bomb.

A ceremony, attended by Japanese Prime Minister Shinzo Abe, was held at Hiroshima's memorial park before thousands of lanterns are released on the city's Motoyasu river.

On Thursday at 8:15am, the exact time when the bomb, dropped by the US B-29 aircraft, the Enola Gay, exploded on 6 August, 1945, the crowd stood for a moment of silence.

In the heavy summer heat, cicadas shrilled, the Peace Bell rang and hundreds of doves were released into the sky.

The Hiroshima bombing, which killed 140,000 by the end of the year, was followed three days later by the bombing of Nagasaki on 9 August, which killed about 40,000 instantly. The war ended on 15 August.

The bombings remain the only use of nuclear weapons for warfare in history.

The cities of Hiroshima and Nagasaki became known for cancers, premature births and malformed babies.

About 90 percent of the city was destroyed, which is why it looks so new today.

Addressing 40,000 people who attended the commemoration ceremony at Hiroshima's peace park near the epicentre of the 1945 attack, Abe called for worldwide nuclear disarmament.

He said that that atomic bomb not only killed thousands of people in Hiroshima but also caused unspeakable suffering to survivors.

"Today Hiroshima has been revived," Abe said, "and has become a city of culture and prosperity.

"Seventy years on I want to reemphasise the necessity of world peace."

Seventy years after the devastating attack, Abe's efforts to pass security bills that could send troops into conflict for the first time since World War II sparked massive protests around the country.

Critics who see the measures as a derailment of Japan's pacifist constitution lambasted Abe at a meeting after the commemoration ceremony. Abe said the legislation was essential to ensure Japan's safety.