South Korea is keeping a close eye on North Korea’s port of Jangjeon amid increased sightings of North Korean warships in the area.

According to a government-related agency on Wednesday, recently there have been signs that suggest the North is aiming to use the port as a military base. The port was where South Korean ferries docked when there were tours to Mount Geumgang. 

The agency said new dock facilities and a building have been built at the port and more warships have been spotted there compared to the past.  

Back in 2017, satellites captured images of three hovercraft anchored at the port.

Before tourism to Mount Geumgang was launched, the port had served as the North’s southernmost naval base with warships and submarines.  

The North moved the base and deployed warships to other ports after full-scale tours to Mount Geumgang launched in the late 1990s.  

A South Korean military official said South Korean and U.S. authorities are closely watching activities at the port but stopped short of providing any more details.