North Korea launched the missiles, presumed to be Scuds, from a site in Hwanghae province in a northeasterly direction at 4 a.m. and 4.20 a.m., Xinhua reported, citing South Korea's joint chiefs of staff.
Hwanghae province is located in North Korea's western region. The missiles flew some 500 km across North Korean territory into its eastern international waters.
Pyongyang failed to issue a no-fly, no-navigation warning before the missile launches, endangering civilian ships and airplanes possibly flying through the region when the missiles were fired.
It was the country's 13th launch of missiles or artillery shells this year.