KNS/AFP/Getty Images

The Internet was abuzz with rumors today that North Korea's newly installed leader, Kim Jong Un, was assassinated during a trip to Beijing, but U.S. officials are debunking the reports as not true.

Several U.S. officials contacted by ABC News said there was no validity to the reports that originated on a Chinese social media site and soon spread to Twitter.

"There's nothing to this, " said one U.S. official, who added that there were no indications that the reports were true.

Another U.S. official said, "Our experts are monitoring the  situation and we see no abnormal activity on the [Korean] peninsula and nothing that credits that tweet as accurate."

North Korean troop movements on the North Korean side of the border are often an indicator that the country's leadership is preparing for tense situations, much as what happened when Kim Jong Un assumed power late last year.

Sina Weibo, a Chinese equivalent  of Twitter, saw a spike in traffic repeating uncorroborated reports that Kim had been assassinated during a visit to Beijing.

The story gained traction on Twitter with re-tweets of what appeared to be confirmation of the reports by two BBC Twitter accounts.  However, a BBC Web article reported those  twitter handles were fakes and have since been closed.

Today's Internet rumors were not the first time that Kim has been the focus of social media rumors.   In early January, postings to Sina Weibo began to appear claiming that Kim had been overthrown in a military coup.  Since then, the Chinese government has been eliminating those postings from the site.   The same is happening with today's rumors on the social media site.

There were also rumors that Kim Jong Un had ordered the assassination of his half-brother, Kim Jong Nam, the eldest of Kim Jong Il's children, who was passed over as his successor.