TAIPEI, Taiwan -- Taiwan's military has declassified documents about the island's secret plans to retake the Chinese mainland in the 1950s -- including a plan to fire nuclear artillery shells at a Chinese port -- a newspaper reported Sunday.

Hoping the U.S. military would provide it with nuclear weapons technology, the Taiwanese army drew up a plan in 1958 to fire nuclear shells at China's southern port of Xiamen from the nearby Taiwanese-held islet of Kinmen, the United Evening News quoted the documents as saying.

The report said the U.S. military first worked on the plan with Taiwan's army but later backed off, fearing such an attack could cause a heavy death toll in China and could also prompt China to seek nuclear technology from the Soviet Union. The Defense Ministry had declassified some documents for use by academics and researchers, but not to the public, a ministry official said on condition of anonymity Sunday.

The official declined to comment on the newspaper report.

Officials at the U.S. representative office in Taiwan could not be reached for comment Sunday.

Gen. Chiang Kai-shek and his Nationalists fled to Taiwan after losing a civil war to Mao Zedong's communist forces in 1949. Chiang built Taiwan into an anti-communist bastion and pledged to retake the mainland.

But after Chiang died in 1975, his son and successor, President Chiang Ching-kuo, focused more on building the island's economy and defenses against a feared invasion by China.

The newspaper report said the Taiwanese army had also made detailed plans to launch a massive landing in southern China in 1956, involving infantry, marines, paratroopers and a tank unit. But the U.S. military refused to offer logistical support and the plan was dropped, the report said.

Citing the declassified documents, the newspaper said Taiwan also sent troops and planes to Indonesia in 1958 to help anti-communist rebels fighting the left-leaning government. Taiwan also sent warplanes to help anti-communist forces in Yemen in 1962, the report said.