The military on Thursday retrieved what is believed to be debris from the rocket North Korea launched earlier this week.

Three pieces of what seems to have been the rocket's combustion gas jet nozzle were recovered from waters some 105 kilometers off Ochung Island in the Yellow Sea, according to the Navy.

The debris was found in the ocean floor off the island located about midway along the west coast of South Korea, the Navy said.

On Sunday, North Korea launched a long-range rocket carrying an Earth observation satellite in what the outside world believes was a test of the country's long-range missile technology.

The rocket successfully put the satellite into orbit, although whether it is running normally has not yet been verified.

The first stage of the rocket and the fairing landed in waters near South Korea as it flew over the Yellow Sea and Japan towards the direction of the Philippines. (Yonhap)