North Korea launched an unspecified ballistic missile toward the East Sea on Wednesday night after South Korea partially suspended a 2018 inter-Korean military agreement aimed at reducing cross-border tensions.

South Korea’s Joint Chiefs of Staff(JCS) said on Thursday that the North fired the missile from the Sunan area of Pyongyang at 11:05 p.m. Wednesday, and the launch appears to have failed.

The JCS added that the intelligence authorities of South Korea and the United States are conducting an analysis of the launch.

Earlier on Wednesday, Pyongyang said it successfully launched the Malligyong-1 satellite on a Chollima-1 rocket at 10:42 p.m. Tuesday and placed the satellite in orbit.

In response, South Korea’s defense ministry suspended the effectiveness of Article One, Clause Three of the military agreement as of 3 p.m. Wednesday and immediately resumed surveillance operations along the heavily fortified border with the North.

The clause in question established a buffer zone by designating a no-fly zone along the inter-Korean border area.