Nuclear-armed North Korea has fired three short-range missiles off its west coast, Yonhap news agency reported Saturday, threatening new military tensions with its neighbours.
The South Korean agency, quoting a government source, said the missiles were fired on Friday into the Yellow Sea off Jeungsan County, some 40 kilometres west of Pyongyang.
The second test by the hardline Communist country in two months was part of a training exercise involving Russian-designed Styx ship-to-ship missiles with a range of 46 kilometres, the report said.
"The missile launch, like the test-firing conducted on March 28, is part of normal military training aimed at testing the performance of the missiles and improving operational readiness," the unnamed source was quoted as saying.
A South Korean defence ministry spokesman refused to comment on the missile launches, which coincide with rising cross-border tensions following this year's change of government in Seoul.
"We don't comment on any matter of intelligence," the spokesman said.
The source quoted by Yonhap said the missiles were fired toward the northeast from a ship in the Yellow Sea as North Korea prepares for annual military exercises in August, adding they were not directed at the South.
"And they were short-ranged. Therefore, we don't think they were aimed at threatening the South. We believe it was part of preparations for the summer military exercise," the source was quoted as saying.
North Korean military usually carries out inspections of its equipment in May and June ahead of the summer exercises by test-firing short-range missiles and ammunition and carrying out drills, Yonhap said.
The latest launch coincided with a warning from the North's military that inter-Korean relations could fall into an "uncontrollable catastrophic phase" if the South continued scattering anti-Pyongyang leaflets on its territory.
It accused Seoul of using balloons to send propaganda leaflets across the heavily fortified inter-Korean border.
The South's defence ministry said it stopped sending leaflets in 2004 but individual groups including Christians and North Korean defectors continued the practice.
Inter-Korean relations have soured after President Lee Myung-Bak took office in February, replacing 10 years of liberal rule with a conservative government.
North Korea fired three or four missiles of the same type on March 28 in what was described then by the South Korean government as "part of a regular military exercise."
North Korean military tests have shaken the region previously, particularly in 1998 when Pyongyang fired over Japan's main island prompting Tokyo and Washington to start work on an advanced missile shield.
North Korea staged a nuclear test in October 2006. Last year, it struck a landmark six-party deal last year with the United States, China, Japan, Russia and South Korea aimed at dismantling its atomic arsenal.
Under the deal, it agreed to disable nuclear plants at its key Yongbyon facility in exchange for aid and diplomatic recognition.
As part of that agreement, Pyongyang was to hand over a full declaration of all its nuclear activities by December 31 last year.
But disputes over the declaration have blocked the start of the final phase of the process – the permanent dismantling of the plants and the handover of all atomic material.