North Korea fired what appeared to be cruise missiles off its east coast and air-to-ground missiles from fighter jets into the East Sea on Tuesday, South Korea’s military said, in muscle-flexing maneuvers on the eve of the late national founder’s birthday and the South’s general elections.

The surface-to-ship cruise missiles were fired northeastward from areas near its eastern coastal town of Munchon at around 7 a.m. during a time period of more than 40 minutes, the Joint Chiefs of Staff (JCS) said, adding they flew around 150 kilometers before splashing into waters off the east coast.

Along with the missile launches, the North also flew multiple Sukhoi-variant fighter jets above the eastern coastal city of Wonsan, and fired multiple anti-ground missiles into the East Sea, the JCS added.

It was not immediately known if leader Kim Jong-un guided the latest firings.

"The military is closely monitoring the situation for possible additional launches, while maintaining a readiness posture," the JCS said in a release.

The firings came on the eve of the 108th birthday of Kim Il-sung, the North’s late national founder and grandfather of current leader Kim Jong-un, and South Korea’s parliamentary elections.

The founding leader’s birthday is one of the North’s biggest national holidays along with the birthday of the current leader’s father, Kim Jong-il, and the communist nation has often held massive parades and other military events to celebrate the holiday.

It is the latest in a series of military actions by the North, as the regime has sought to beef up defense capabilities amid stalled denuclearization talks with the United States and heightened vigilance against the coronavirus.

The last known test of cruise missiles took place on June 8, 2017, when the North carried out the first-ever test of its Kumsong-3 coastal defense cruise missile from Wonsan. The system is known as the KN-19 by the US, and was first seen at a military parade held in Pyongyang on April 15 of the year to mark the 105th birthday anniversary of the founding leader.

"The projectiles fired today appear to be similar to those fired in June 2017. More analysis is under way by the South Korean and the US intelligence authorities," a JCS officer told reporters. (Yonhap)