Japan's public broadcaster mistakenly sent an alert warning citizens of a North Korean missile launch and urging them to seek immediate shelter, then retracted it minutes later, days after a similar error in Hawaii.

NHK television issued the message Tuesday on its internet and mobile news sites as well as on Twitter, saying North Korea appeared to have fired a missile at Japan. It said the government was telling people to take shelter.

The false alarm came two days after Hawaii's emergency management department sent a mistaken warning of a North Korean missile attack to mobile phones across the state, triggering panic.

NHK deleted its tweet after several minutes, issued a correction and apologized several times on air. It said a mistake in using the alert system caused the error.