North Korea has caused shock and anger among its neighbours and the rest of the world by launching a long-range rocket which flew over Japan and landed in the ocean near the Philippines.

The North launched the rocket about 9:52am local time, close to the first anniversary of the death of former leader Kim Jong-il, and as elections loom in South Korea and Japan.

The test has been condemned by the South, the United States, Japan, China and Russia, among others, as a means of testing a long-range missile that could one day deliver a nuclear warhead.

The first stage of the rocket splashed into the Yellow Sea, the second stage dropped into the East China Sea, and the final stage plunged into the Pacific east of the Philippines, all as planned.

The Japanese government said the rocket had passed over Okinawa, south of the Japanese mainland, but said it had not followed through with earlier threats to shoot it down because there was no threat from rocket debris.

North Korea said its satellite had been successfully placed into orbit.

"The launch of the second version of our Kwangmyongsong-3 satellite from the Sohae Space Centre... on December 12 was successful," the Korean Central News Agency (KCNA) said.

"The satellite has entered the orbit as planned," it added.

The same statement was later read out on North Korean state television.

A South Korean TV mock-up shows the rocket's projected flight path ( AFP: Jung Yeon-Je )

The rocket was detected by US missile-warning systems, and officials at the North American Aerospace Defence Command (NORAD) said the rocket deployed an object that appeared to achieve orbit around the Earth.

The launch came just one day after satellite imagery suggested the rocket was being partially dismantled after reportedly suffering from technical faults.

In a statement carried on North Korean state media on Sunday, the country's space technology committee said it was considering postponing the launch because of possible technical problems.

But the eventual launch came within a window previously announced by the secretive state.

An earlier launch in April ended in failure after the rocket crashed into the sea shortly after launch.

The launch of the rocket violates United Nations Security Council resolutions, and the Security Council will meet early tomorrow at the request of Japan and the US.

South Korea and Australia have condemned the launch, with Prime Minister Julia Gillard and Foreign Affairs Minister Bob Carr issuing a joint statement calling the launch "a provocative and irresponsible act which has allowed North Korea to again test its ballistic missile technology".

The White House labelled the launch a "highly provocative act" and vowed to work with international partners to seek "appropriate action" against Pyongyang.

North Korea has carried out a successful long-range rocket test, in defiance of international pressure.

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