North Korea launches rocket after satellite warning

North Korea has launched a rocket shortly after announcing it planned to send up its first space satellite, sources in Japan and South Korea say.

Japan issued a warning to residents in the southern prefecture of Okinawa but later reported there was no danger of the rocket hitting its territory, reports BBC.

North Korea said earlier it planned to launch a satellite by 11 June to monitor US military activities.

Japan said it was ready to shoot down anything that threatened its territory.

Residents of the South Korean capital Seoul awoke on Wednesday morning local time to air raid sirens and a message telling them to prepare to evacuate. Authorities then retracted the message saying it had been sent in error.

South Korea's military said the projectile might have broken up in mid-air or crashed after it vanished from radar early, adding that analysis was being conducted, Yonhap news agency reports.

On Tuesday, Ri Pyong Chol, vice chairman of North Korea's ruling party's central military commission, announced the launch plan, saying it was in response to "reckless military acts" by the US and South Korea.

He accused the countries of "openly revealing their reckless ambition for aggression".

Before Wednesday's launch, the US state department said any North Korean launch that used ballistic missile technology would violate multiple UN Security Council resolutions.