Two armed North Korean soldiers briefly crossed the heavily fortified inter-Korean border last week in what is believed to be the pursuit of a North Korean defector.

According to military sources on Friday, the two soldiers, armed with rifles, crossed the Military Demarcation Line(MDL) and advanced to about 200 meters from a South Korean guard around 2 p.m. or 3 p.m. Sunday, hours after a North Korean soldier crossed the MDL on the central front and expressed his intention to defect.

South Korean troops issued warning broadcasts and fired warning shots at the two North Korean soldiers, believed to be a pursuit team sent to capture the defector, and prompted them to retreat across the border.

At the time of the defection, South Korea’s Joint Chiefs of Staff(JCS) said there had been no unusual movement by North Korean troops in relation.

The JCS explained that the North Korean soldier had defected around 7 a.m. that day, while the two armed North Korean soldiers had crossed the MDL around noon.

The JCS said that, given the approximate five-hour gap, it was unclear whether the soldiers were part of a pursuit team, and based on its own assessment, it had chosen not to release the information at the time.