Paper lanterns float in the river at the Peace Memorial Park in Hiroshima, Japan, Aug. 6, 2019. Hiroshima, the Japanese city hit by a U.S. atomic bomb at the end of the World War II, marked the 74th anniversary of the bombing on Tuesday. (Xinhua/Du Xiaoyi)

Thousands of people have signed an online petition against the planned demolition of two early 20th-century­ buildings that remained intact after the atomic bombing of ­Hiroshima devastated the Japanese city.

A local government official said Tuesday they had received the petition signed by 12,000 citizens calling for the preservation of the buildings that stand 2.7 kilometers from the 1945 blast.

The three-story red-brick buildings are part of a cluster of four built in 1913 and used to manufacture Japanese military uniforms.

A routine earthquake inspection two years ago revealed they would not withstand a strong tremor. "There was no choice for us not to take any measures as a collapse could hurt residents in the neighborhood," said the official, who declined to give his name.

The local authorities own three of the cluster of four buildings and the national government owns the remaining property.

Preserving and strengthening all three buildings owned by the local government would cost 8.4 billion yen ($77 million), they estimate.

They propose to demolish two of the buildings and strengthen the remaining one they own, at a lower estimated cost of between 1.4 and 3.1 billion yen.

But this has proven unpopular locally, with the online petition now attracting nearly 15,000 signatures.

The Hiroshima Peace Memorial, or Genbaku Dome, is the most famous structure left standing after the world's first atomic bomb exploded on August 6, 1945.