Japan's public broadcaster NHK's false alarm about a North Korean missile launch which was received on a smart phone is pictured in Tokyo, Japan January 16, 2018. Reuters

TOKYO: The Japanese government called on public broadcaster NHK on Wednesday to make sure a false alarm warning of a North Korean missile launch will not be repeated, with tensions still high because of the North?s missile and nuclear programs.

NHK issued an erroneous alarm on its website on Tuesday evening, saying North Korea appeared to have launched a missile and urging people to take shelter. A similar gaffe caused panic in the US island state of Hawaii at the weekend.

Japan?s public broadcaster put out another message on its website within five minutes correcting itself and said no government warning, known as a ?J-alert?, had been issued.

?The J-alert system is information of extreme importance in maintaining the security and safety of the people, so we?ve asked that they ensure this does not happen again,? Chief Cabinet Secretary Yoshihide Suga told a regular news conference.

There have been no reports of panic or other disruptions following the NHK report.

NHK said the false alert was sent by mistake when it was trying to issue another news flash.

The broadcaster declined to say what the other news flash was about, but some domestic news outlets issued bulletins at around the same time about the latest recipients of a Japanese literary award.

NHK is looking into measures to prevent a recurrence but could not comment on specific details because the plan had not been firmed up yet, an NHK spokeswoman said.

The false alert was also sent to mobile phone users of NHK?s online news distribution service. It was not clear how many of its 300,000 users have a function to let news alerts pop up on the cellphone screen when activated, NHK said.