The JCS said in a statement that the South Korean military detected short-range projectiles of multiple types, which were launched northeastward from areas near the DPRK's eastern town of Sondok in South Hamgyong province at about 7:36 a.m. local time.
The projectiles flew as far as around 200 km at a maximum altitude of some 50 km. The intelligence authorities of South Korea and the United States were analyzing further details, the JCS said.
The JCS noted that the launches were seen as the part of the DPRK's joint strike exercises, involving multiple rocket launchers of multiple types, for a wintertime drill following the previous ones on Feb. 28 and March 2.
A week earlier, the DPRK fired two short-range projectiles, which traveled about 240 km at an altitude of some 35 km, into the eastern waters.
The JCS said the South Korean military was closely monitoring relevant situations in preparation for possible further launches while maintaining a thorough defense readiness.
It expressed strong regrets over the DPRK's projectile launches, adding that such acts run counter to the basic spirit of the inter-Korean military agreement in which the two sides agreed on defusing military tensions and building trust on the Korean Peninsula.
The military agreement was signed during the third summit between South Korean President Moon Jae-in and top DPRK leader Kim Jong Un that was held in Pyongyang in September 2018.