The launch took place about 5 a.m. local time, or 4 p.m. Saturday ET, a South Korean Defense Ministry official told CNN.
The two scud-type missiles flew about 310 miles and landed in waters between North Korea and Japan.
It was the second such missile testing North Korea has conducted since Thursday. The country has a reputation of launching missiles during military exercises or when it wants to raise tensions in the region.
"We call on North Korea to refrain from taking provocative actions and instead fulfill its international obligations and commitments," a U.S. State Department official told CNN in reaction to the launch.
The United Nations banned such launchings by North Korea out of fear the country was developing a longer-range missile with a nuclear warhead.