North Korea fired two short-range ballistic missiles from its east coast Wednesday, the South Korean military said, less than a week after the launch of two similar weapons as it looks to heap pressure on Seoul and Washington to halt upcoming joint military drills.

South Korea's Joint Chiefs of Staff said in a statement that both missiles were estimated to have flown about 250 km at an altitude of roughly 30 km. The first missile was launched at 5:06 a.m., and the second at 5:27 a.m., from the Kalma area near the eastern port of Wonsan, the JCS said, adding that the South Korean and U.S. militaries were continuing to analyze the launches.

The South Korean military said Wednesday's launches were of weapons similar to the new type of missiles launched six days ago. Seoul said both of those missiles traveled 600 km, and that flight data of the weapon, known as the KN-23, showed similarities to the Russian-made Iskander, a short-range, nuclear-capable missile.