By DPA
Tokyo/Seoul : North Korea fired a number of short-range missile Friday morning towards the Sea of Japan, South Korea's military confirmed.
The South Korean general staff said the launches were possibly within the framework of the annual military exercises conducted by the North Korean armed forces.
The military said that work was underway to determine the number and type of missiles fired.
Earlier, Japan's Kyodo News agency, citing unnamed Japanese and US sources, reported that the weapons were short-range surface-to-ship missiles and were believed to be a modified version of the Silkworm missile or a ballistic missile smaller than a Scud. Such missiles have a range of about 100 km.
The agency added that the launches originated from the east-central coastal province of South Hamgyong in information that was believed to be based on US military satellite images.
Japanese Prime Minister Shinzo Abe said the missile launches were no "serious threat" to Japan's security.
The launches might have been part of a regular drill, the sources speculated, but the motive behind them, the number of missiles launched and where they landed was being investigated.
News of the missile firings followed Friday's launch of South Korea's first destroyer equipped with the Aegis ballistic-missile combat system, aimed to strengthen its defence capabilities against North Korea.
North Korea conducted seven test launches of missiles in July over the Sea of Japan, also known as the East Sea, including a long-range rocket believed to be capable of reaching US territory. The action drew international condemnation and sanctions ahead of North Korea's first nuclear test three months later.
Rebukes over the nuclear test as well as signs of a willingness to compromise on the part of the US led Pyongyang back to the negotiating table. It agreed to begin dismantling its nuclear programme in a February agreement, but the implementation of that pact has stalled as North Korea awaits the release of North Korean funds frozen by US sanctions.