South China Sea
© Roy IssaAll calm in the South China Sea, with claims by a far-right American website of an explosion involving a US submarine dismissed
A United States defence official has rebuffed online reports by a far-right American radio host and blogger of an explosion involving a US submarine in the South China Sea.

"We have seen no indication that the reports were credible," the official told the South China Morning Post in response to claims by the Hal Turner Radio Show - a far-right American political site which has previously been accused of spreading fake news and conspiracy theories - that oceanographic instruments monitoring the South China Sea had registered a significant undersea explosion.

Quoting unnamed military sources, the Turner website also said there were significant radiation readings around the area of the alleged explosion, and even posted questions on whether China had detonated a nuclear device to warn Washington following the passage of legislation in support of the ongoing anti-government protests in Hong Kong.

A Russian website vpk-news.ru also reported on the alleged explosion and increase in radiation levels.

The claims were quickly picked up and spread on social media platforms such as Twitter, with some users urging people to be aware of the radiation risks. A mainland Chinese news website also carried the report on Friday, but later deleted it.

Mainland online users reacted calmly. "No mainstream media reported about it. It should be unconfirmed rumours," said one user on China's Twitter-like Weibo social media platform. Some other Weibo users checked an official Chinese government website, and found there was no significant change in radiation level around the area.

Greg Poling, director of the Asia Maritime Transparency Initiative under the Centre for Strategic and International Studies, said the explosion could be treated as a rumour, given it was reported by a far-right political site.

"Think you can safely disregard this unless some reputable source corroborates," he said.