More than 250 protesters rode their bicycles on an 11-km loop of Washington on Sunday, the 70th anniversary of the Nagasaki A-bomb attack, to call for the global abolition of nuclear weapons.

The event was organized by anti-nuclear advocate group Global Zero. Similar events were held in Germany, India, Pakistan and Cyprus.

The Washington event started at the White House and encircled a large area that could potentially be devastated if an atomic bomb were dropped on the capital.

Prior to the start of the ride, an official from Global Zero emphasized that the world has been exposed to the fear of nuclear weapons for 70 years, and asked President Barack Obama to work harder to achieve a world without nuclear weapons.

Former U.S. Assistant Secretary of Defense Lawrence Korb addressed the crowd, saying, "It's important to make sure that you keep this issue (nuclear abolition) on the agenda."

Medical researcher Luis Mier, 37, said he believes it is possible for the world to be free of nuclear weapons.

"We need to do more to push the leaders to act in that direction," he said.