"One was fired at 5:20 p.m. and the other at 6:00 p.m. from Sinsang-ni" near the eastern coastal city of Wonsan, South Korean defense ministry spokesman Won Tae-jae told Yonhap.
The report gave no further details. News cable channel YTN carried a similar report.
South Korea's Joint Chiefs of Staff could not immediately confirm the reports.
North Korea had earlier issued a no-sail zone in waters off its east coast through July 10, viewed as a prelude to such missile tests.