The Democratic People's Republic of Korea (DPRK) fired several short-range guided missiles into the sea off its east coast on Friday in an apparent test launch, the Republic of Korea (ROK) officials and media reports said.

ROK's Joint Chiefs of Staff confirmed the launches, but said it was still investigating how many missiles were fired. The launches were apparently part of annual exercises conducted by the DPRK, the Joint Chiefs said in a statement.

"The short-range missile launches are believed to be part of a routine exercise that the DPRK has conducted annually on the east and the west coasts in the past," the statement said.

The missiles were fired from the country's east coast into the sea between Japan and the Korean Peninsula, a Joint Chiefs official said on condition of anonymity, citing official protocol.

Japan's public broadcaster and other media, citing Japanese and US sources, reported the missiles were surface-to-ship. Japan's Defense Ministry and Foreign Ministry could not immediately confirm the reports, but were investigating.

Analysts and media reports said the DPRK's test was in response to the ROK's launch of its first destroyer equipped with high-tech Aegis radar technology on Friday. The ROK is now one of only five countries armed with the technology, which will greatly enhance the South's ability to locate, track and shoot down aircraft and missiles from other countries.

"The DPRK fired them as a warning as a response to ROK's deployment of Aegis-equipped destroyer," said Toshimitsu Shigemura, an expert on DPRK issues at Japan's Waseda University. "This shows the DPRK, whose navy is rather small, is extremely alarmed."

Japanese Prime Minister Shinzo Abe called the tests "extremely regrettable" but said, "We do not consider (the missile firing) as a serious threat to Japan's national security."

Public broadcaster NHK said the missiles were shorter-range, and were not the DPRK's existing Rodong or Taepodong I ballistic missiles.

Source: China Daily/agencies