SEOUL, March 21 (Yonhap) -- North Korea on Saturday fired two projectiles presumed to be short-range ballistic missiles toward the East Sea, South Korea's Joint Chiefs of Staff (JCS) said, the latest in a series of such launches this month.

They were fired from areas in its western province of North Pyongan earlier in the day, the JCS said, without providing more details.

"Our military is monitoring the situation in case there are additional launches and maintaining a readiness posture," the JCS said.

It is the third time that the communist country has carried out such weapons tests in March after months of hiatus.

The last such test took place on March 9 when it fired at least three short-range projectiles believed to have come from a super-large multiple rocket launcher, which came a week after the firing of two short-range projectiles of the same type, according to the JCS.

The previous rounds, which occurred under the guidance of leader Kim Jong-un, appear to have been part of its artillery strike drill for the wintertime exercise, JCS officers said, noting that the drill is likely to continue throughout this month.