The projectiles were fired at 6.45 a.m. and 7.02 a.m. from the town of Sondok in South Hamgyong province into the East Sea, and both flew around 380 km at a maximum altitude of 97 km and a top speed of around Mach 6.5, Yonhap News Agency quoted the Joint Chiefs of Staff (JCS) as saying in a statement.
"Our military is monitoring the situation in case of additional launches and maintaining a readiness posture," the JCS statement said, adding the South Korean and the US intelligence authorities were analyzing their exact type.
Saturday's firings marked the seventh round of such launches since July 25 when the North broke a 17-month hiatus and started firing missiles and projectiles to test new weapons and protest the South-US joint military exercise that it has long denounced as a rehearsal for invasion.
The exercise concluded earlier this week, Yonhap reported.
The last missile firing was conducted on August 16.
The North is believed to use these launches to test new types of short-range missiles, including its versions of the Iskander and the US' Army Tactical Missile System (ATACMS).
The peak altitude of the previous projectiles launched by the North this year had ranged from 25 km to 60 km.
The South Korean military also noted that it will share its confidential information on the latest launches with Japan upon Tokyo's request under the framework of the bilateral intelligence-sharing pact of the General Security of Military Information Agreement (GSOMIA).
In Washington, a senior government official said the US was aware of the latest missile launches and was closely monitoring the situation in cooperation with its allies.
( With inputs from IANS )