North Korea fired two unidentified projectiles from the eastern coastal city of Wonsan on Monday, South Korea's defence ministry said.
"The military is monitoring for additional launches and maintaining readiness," said South Korea's Joint Chiefs of Staff.
They were unable to confirm how far the projectiles flew or whether it was ballistic or rocket artillery.
The launches come just days after North Korea's Kim Jong-Un oversaw military drills.


US military to begin Iran maritime blockade on Monday
Orban ousted after 16 years as Hungarians flock to pro-EU rival
Trump vows to blockade Strait of Hormuz after Iran peace talks stumble
Nigerian airstrike hits market, 200 feared dead
Russia, Ukraine trade accusations of ceasefire violations
