North Korea fired multiple ballistic missiles toward the East Sea on Tuesday, according to South Korea's Joint Chiefs of Staff (JCS).

The South Korean military detected multiple ballistic missiles launched toward the East Sea from areas north of Pyongyang at around 3:50 p.m. 

The JCS said the missiles flew about 350 kilometers, adding that it is currently analyzing more details of the projectiles with the United States.

The JCS said the military has strengthened vigilance and monitoring in preparation for additional launches while maintaining a firm readiness posture through the sharing of intelligence with the U.S. and Japan. 

This is the second time this year the reclusive state has launched ballistic missiles since January 4.

Observers believe the North's latest projectile launch is aimed at boosting internal solidarity ahead of the Ninth Congress of the ruling Workers' Party, which is expected to take place next month, as well as showcasing its presence externally. 

Tuesday's launch also comes as U.S. Under Secretary of War for Policy Elbridge Colby is visiting Seoul and Tokyo.