Japanese national broadcaster NHK issued a false alert about a North Korean missile launch, adding to questions about the reliability of early-warning systems after a similar incident in Hawaii.

The broadcaster issued a “J-Alert” at 6:55 p.m. Tuesday via its app and website, urging people people to take cover inside buildings or underground. NHK corrected the error at 7:00 p.m. While its television channels didn’t cover the initial alert, an apology was subsequently issued on its scheduled evening news program, as well as on its website.

The error in Japan comes after Hawaiian residents -- already anxious about months of nuclear saber-rattling between U.S. President Donald Trump and North Korea’s Kim Jong Un -- were sent into a panic after an alert Saturday morning, later found to be caused by human error.

There were no immediate signs of panic in Tokyo after the alert was issued. North Korea has fired numerous missiles into the waters around Japan in recent months, including some over the country.

Few Japanese followed official warnings to take shelter following the launch of North Korean ballistic missiles in August and September, a Japanese government survey found. Just 5.6 percent of respondents said they took shelter after North Korea fired on Sept. 15. The most common reason respondents gave for not evacuating was that there was “no point,” or that they didn’t know where to go.