At 12:16 p.m. local time, terminals at government agencies, municipalities and media organizations across Japan flashed news from the government: "North Korea appears to have launched a projectile." Almost immediately TV stations broke into programming to deliver the news and soon after it flashed around the world.

Too bad North Korea hadn't actually launched anything. Five minutes later the same network was used to retract the warning.

The error was blamed on a misunderstanding between military staff. A radar station near Tokyo had detected something over the Sea of Japan, which separates the two countries and over which the rocket was expected to fly, and this was relayed to Japan's Air Defense Command. But there, according to local media reports, it was mistaken for data from a U.S. early warning satellite and passed on to the Defense Agency and central government and the alert was issued.

The incident was an embarrassment for the Japanese government and has done nothing to calm nerves in Japan ahead of the launch.

"We caused a great deal of trouble to the Japanese people," said Defense Minister Yasukazu Hamada. "I want to apologize to the people from my heart."