North Korea fired several short-range guided missiles into the sea off its east coast Friday in an apparent test launch, South Korean officials and media reports said.

South Korea'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 North, the Joint Chiefs said in a statement.

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

The missiles were fired from the communist 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 U.S. sources, reported the missiles were surface-to-ship. Japan's Defense Ministry and Foreign Ministry could not immediately confirm the reports, but were investigating.

Complete coverage is available in FOXNews.com's North Korea Center.

Some reports suggested the North's test was in response to South Korea's launch of its first destroyer equipped with high-tech Aegis radar technology on Friday.

South Korea's Yonhap news agency cited an unidentified Unification Ministry official as saying the tests would not strain ties because they were apparently part of regular exercises. North and South Korea are planning to hold Cabinet level talks on reconciliation efforts next week in Seoul.

"I understand that North Korea test fires short range missiles every year. It's not likely to have any immediate effect on inter-Korean relations," the official was quoted as saying.

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

It was not immediately known where the missiles landed.

Kyodo News agency said the missiles were launched from Hamgyong Namdo on the east coast of the Korean Peninsula and are considered modified silkworm or miniaturized Scuds, with a range of about 60-125 miles.

Mobile missile carriers, communication equipment and personnel had been seen in the area before the launch, but they left after the missiles were fired, Kyodo said.

Last month, North Korea displayed a newly developed ballistic missile capable of reaching the U.S. territory of Guam during a massive military parade.

The parade in Pyongyang featured three new models, including the medium-range missile that can travel 1,500-2,500 miles, the South Korean newspaper Chosun Ilbo reported.

The report cited an unidentified South Korean government official familiar with an analysis of U.S. satellite images.

North Korea's missile program has been a constant concern to the region, along with its pursuit of nuclear weapons.

The hard-line regime test-fired a series of missiles in July last year, including its latest long-range model, known abroad as the Taepodong-2, which experts believe could reach parts of the United States.

The North rattled the world again in October by conducting its first-ever test of a nuclear device. However, experts believe it does not have a bomb design advanced enough to be placed on a missile.

Complete coverage is available in FOXNews.com's North Korea Center.