In photos: 78 years since atomic bombs drop on Hiroshima and Nagasaki
The Hiroshima bombing destroyed everything within 1.5 kilometres (1 mile) of ground zero and created searing heat of 3,000 degrees Celsius (5,432 degrees Fahrenheit) at its centre.
Remembering Hiroshima
On August 6, 1945, during the Second World War, the United States dropped an atomic bomb named "Little Boy" on the Japanese city of Hiroshima. This devastating aerial bombing resulted in the deaths of at least 140,000 people, mostly civilians, including several women and children.
The atomic bomb named "Little Boy" that was dropped in Hiroshima, claimed the lives of at least 140,000 people.
After the Hiroshima catastrophe, three days later, another atomic bomb named "Fat Man" was dropped on the city of Nagasaki, resulting in the immediate death of over 75,000 people.
However, not all of the casualties were caused by the blasts of the bombs. Thousands more perished in the weeks and months that followed due to radiation sickness, severe burns, and other injuries.
Shortly after the first bombing, another atomic bomb named "Fat Man" was dropped on the city of Nagasaki.
Many died without getting medical support, those who went to the city for help died from radioactive rain.
It is known that the reason then-US President Harry Truman ordered the use of atomic bombs was to offset the Soviet threat in East Asia and Eastern Europe, as well as to make a show of strength to the USSR.
Thousands more perished in the weeks and months that followed, suffering radiation sickness, devastating burns and other injuries
While the Americans announced that the death toll from the atomic bombings was 117,000, the Japanese said it was close to half a million. Survivors, called "Hibakusha," suffer from cancer, disfigurement, and hard-to-treat diseases.
The bomb destroyed 70 percent of Hiroshima.
After the bombings, Japan surrendered on August 15, 1945, marking the end of World War II.
Japan surrendered shortly after the twin bombings, marking the end of World War II:
Since the bombings of Hiroshima and Nagasaki in 1945, there has been no recorded instance of one country using a nuclear weapon to attack another nation.
The devastation and human suffering caused by those bombings have led to global awareness of the catastrophic consequences of nuclear warfare, prompting nations to exercise restraint and pursue nuclear disarmament efforts.
Since these bombings, no country has attacked another with a nuclear weapon.
Each year, the city of Hiroshima commemorates the victims of the atomic bombing by observing a minute of silence, ringing a peace bell, and releasing hundreds of doves into the air as symbols of peace and remembrance.
On Sunday, Japan marked the 78th anniversary of the atomic bombing of Hiroshima.
The highlight of the event was the traditional Peace Declaration delivered at the ceremony in the Peace Memorial Park by Hiroshima Mayor Kazumi Matsui, Tokyo-based Kyodo News reported.
Hiroshima honours the victims of the attack every year by observing a minute of silence, tolling a peace bell and releasing hundreds of doves into the air.
Hailing the Group of Seven leaders' landmark visit in May to the Japanese park and its atomic bomb museum, Matsui urged policymakers to abandon the idea that nuclear weapons deter war.
"Leaders around the world must confront the reality that nuclear threats now being voiced by certain policymakers reveal the folly of nuclear deterrence theory," Matsui said, adding: "They must immediately take concrete steps to lead us from the dangerous present toward our ideal world."