A tourist thought a US soldier's mad dash into North Korea was so 'stupid' it had to be a TikTok prank until the guards started shouting 'get that guy'

• A woman who saw a US soldier run into North Korea from South Korea said she thought it was a prank.
• Sarah Leslie told the AP that soldier Travis King's stunt was "the most stupid thing you could do."
• King is believed to be in North Korean custody after he crossed a border into the country.

A tourist from New Zealand who witnessed a US Army soldier's mad dash from South Korea into communist North Korea on Tuesday thought the action was so "stupid" that it had to be a TikTok prank. 

"I assumed initially he had a mate filming him in some kind of really stupid prank or stunt, like a TikTok, the most stupid thing you could do," the witness, Sarah Leslie, told the Associated Press of soldier Travis King. 

Leslie said that she then heard an American guard who was patrolling the area with South Korean troops shout, "Get that guy!"

"People couldn't really quite believe what had happened," said Leslie, adding, "Quite a few were really shocked."

King, who is now believed to be in North Korean custody, "willfully and without authorization" crossed from South Korea over the heavily fortified border into North Korea, US Secretary of Defense Lloyd Austin said.

He was previously held in a South Korean prison for nearly two months over assault charges and was in the process of being brought back to the US before he joined in on a civilian border tour and ran into North Korea, US officials told The Associated Press.

Leslie and some 40 other tourists were visiting the Joint Security Area in the village of Panmunjom moments before King bolted off across the border.

"I probably only saw him running for like a few seconds and that's all it would have taken to get across the board," Leslie told Reuters.