The missiles were fired from the city of Wonsan, where similar launches have occurred, and sources indicate that the projectiles flew a distance of approximately 300 miles.
"The military is keeping close tabs on the situation and prepared to deal with any North Korean provocations," South Korea's Joint Chief of Staff said in a statement.
Earlier on Wednesday, North Korean leader Kim Jong Un claimed that Pyongyang is in possession of miniaturized nuclear warheads.
"The nuclear warheads have been standardized to be fit for ballistic missiles by miniaturizing them," Kim said, according to KCNA, adding "this can be called a true nuclear deterrent."
This week, the Russian Foreign Ministry issued a strong condemnation of North Korea's threat to use preventive strikes.
"In particular, we consider public statements with threats of carrying out some 'preventive nuclear attacks' against one's opponents completely unacceptable," a statement from the Foreign Ministry reads. "Pyongyang must understand that North Korea completely sets itself against the international community, provides the international legal basis for the use of military force against it."
Pyongyang has also expressed outrage over joint military drills between Washington and Seoul. The largest ever conducted, the exercises are meant to mimic a hypothetical invasion of North Korea
The UN imposed new sanctions — the harshest in 20 years — against Pyongyang last week over nuclear tests conducted earlier this year. The DPRK also launched a satellite in February which the UN deemed a veiled attempt to demonstrate its ballistic missile capabilities.
Hours after those new penalties were put in place, North Korea fired short-range missiles into the ocean.