Footage of previous North Korean missile launch (Picture: KCNA).
North Korea has fired two short-range ballistic missiles off its east coast, South Korea's military said.
The launch comes less than a week after Pyongyang's first weapons test since US President Donald Trump and North Korean leader Kim Jong-un met in June.
The North called that launch a "solemn warning" to Seoul over its purchase of high-tech US-made fighter jets and planned military drills which it sees as an invasion rehearsal.
South Korea's Joint Chiefs of Staff said the missiles were launched from the town of Wonsan, on the North's eastern coast.
Both missiles were believed to have flown about 250km (155 miles) at a maximum altitude of 30km (19 miles).
Six days earlier, North Korea fired two short-range ballistic missiles that Seoul officials say flew 600km (370 miles) before landing at sea.
UN Security Council resolutions ban North Korea from using ballistic technology in any weapons launches.
But it is unlikely that the country, which is already under 11 rounds of UN sanctions, will be hit with fresh punitive measures.
Past sanctions were imposed only when the North conducted long-range ballistic launches.
Earlier last week, Mr Kim also visited a newly-built submarine and expressed his satisfaction with its weapons system.
North Korea said its deployment was "near at hand".
Wednesday's launches came hours after a senior US official said President Donald Trump has sent mementoes from his brief visit to an inter-Korean border town late last month to Mr Kim.
The official said a top staffer from the National Security Council hand-delivered photographs from the June Trump-Kim meeting at the Korean demilitarised zone (DMZ) to a North Korean official last week.
The DMZ meeting was the third summit between Mr Trump and Mr Kim.
North Korea suspended nuclear and long-range missile tests after entering talks with the US, which Mr Trump views as proof his policy is working well and eased the danger of a war with the North.