North Korea appears to have fired artillery shots, possibly from multiple rocket launchers, on Sunday afternoon.

The Joint Chiefs of Staff(JCS) said on Sunday evening that it detected flight trajectories presumed to be North Korean artillery from 6:21 p.m. to 6:37 p.m.

The JCS reportedly detected two flight trajectories.

The JCS said the South Korean military maintains a robust readiness in close cooperation with the United States amid boosted surveillance on North Korea.

The firing comes a month after North Korea fired five artillery rounds into the western waters on June 12. Last time the regime fired a ballistic missile was on June 5, when a total of eight short-range ballistic missiles were launched toward the East Sea from four venues including Pyongyang. 

Meanwhile, the presidential National Security Office held a meeting presided over by National Security Adviser Kim Sung-han to check the military's readiness and movements of the North Korean troops.