Japan's public broadcaster NHK issued a false alarm about a North Korean missile launch, just days after a similar gaffe caused panic in Hawaii, but it managed to correct the error within minutes.

Key points: Message was corrected after 5 minutes

Message was corrected after 5 minutes Broadcaster NHK is "still checking" why the message was sent

Broadcaster NHK is "still checking" why the message was sent There were no immediate reports of panic

NHK's 6:55pm alert warned that "North Korea appears to have launched a missile … The Government urges people to take shelter inside buildings or underground".

The same alert was sent to mobile phone users of NHK's online news distribution service and tweeted.

In five minutes, the broadcaster put out another message correcting itself.

It was not immediately clear what triggered the mistake.

"We are still checking," an NHK spokesman said.

NHK deleted its tweet after several minutes, issued a correction and apologised several times on air.

Regional tension soared after North Korea in September conducted its sixth and largest nuclear test and in November said it had successfully tested a new type of intercontinental ballistic missile that could reach all of the US mainland.

The alert sent by Hawaiian authorities went uncorrected for 40 minutes. ( ABC News: David Spicer )

It regularly threatens to destroy Japan and the United States.

There were no immediate reports of panic or other disruption following the Japanese report.

Human error and a lack of fail-safe measures during a civil defence warning drill led to the false missile alert that stirred panic across Hawaii, a state emergency management agency spokesman said.

Elaborating on the origins of Saturday's false alarm, which went uncorrected for nearly 40 minutes, spokesman Richard Rapoza said the employee who mistakenly sent the missile alert had been "temporarily reassigned" to other duties.

Sorry, this video has expired A child was lowered into manhole following false missile warning

Reuters/AP