By Ju-min Park and Satoshi Sugiyama
SEOUL/TOKYO (Reuters) -North Korea fired a salvo of at least 10 short-range ballistic missiles off its east coast, South Korea's military said on Thursday, calling it a possible display for would-be buyers, including Russia.
Japanese Prime Minister Fumio Kishida said North Korea had launched a ballistic missile that appeared to have landed outside Japan's exclusive economic zone.
The suspected missiles were fired from the Sunan area near its capital Pyongyang at 6:14 a.m. on Thursday (2114 GMT on Wednesday) and flew about 350 km (217 miles) before plunging into the sea, South Korea's military said in a statement.
South Korea is sharing North Korean missile-related information with U.S. and Japanese officials, it added in the statement.
The United States called on North Korea to stop "further unlawful and destabilising acts".
The launches were the latest in a series of tests this year by North Korea involving what analysts call "theatre strike missiles," or shorter-range weapons designed to hit targets within a region, as opposed to long-range missiles that might hit enemy cities on other continents.
North Korea has conducted several similar salvo launches of its KN-25 missile this year, including one test where it fired at least six missiles.
Demonstrating such missiles, which the North says can be armed with conventional or tactical nuclear warheads, underscores the threat to South Korea, former U.S. government weapons expert Vann Van Diepen wrote in a report for the 38 North programme this month.
South Korea's Joint Chiefs of Staff said on Thursday that all of the missiles fired appeared to have been the same type, and that they were a type likely destined for export to Russia.
Russia has fired as many as 50 North Korean-made SRBMs at targets in Ukraine, though as many as half lost their programmed trajectories and exploded in the air, Ukrainian officials who examined the debris said.
United Nations sanctions monitors, U.S. intelligence officials, and independent experts have also said that North Korean missiles were used in Ukraine, but Moscow and Pyongyang have denied conducting any arms deals, which would violate an arms embargo on North Korea.
Thursday's launch came after North Korea failed on Monday at its attempt to put a second spy satellite into orbit when a newly developed rocket engine exploded in flight.
After the failure, leader Kim Jong Un pledged never to give up space reconnaissance projects.
On Thursday, a North Korean foreign ministry official condemned U.N. Secretary-General Antonio Guterres' statement that the attempted launch of another military satellite using ballistic missile technology was against U.N. Security Council resolutions.
In another launch watched by its neighbours, North Korea sent hundreds of balloons carrying trash and manure across the heavily fortified border to South Korea on Wednesday, prompting an angry response from Seoul, which said the act was base and dangerous.