The Unification Ministry is keeping a close watch on North Korea ahead of the 65th anniversary of the founding of the communist country’s ruling Workers’ Party.

A ministry spokeswoman made the announcement during a news briefing Wednesday, noting that North Korean state-run news outlets have been reporting on events to mark the anniversary, including a military drill.

North Korean state-run new outlets reported that North Korean leader Kim Jong-il and his heir apparent, Jong-un, visited Tuesday a military unit near Wonsan to observe a drill there. The news outlets said the visit was related to the anniversary, which falls on October tenth.

South Korean intelligence authorities believe that North Korea conducted a massive military drill involving its armed forces off the coast of Wonsan in the East Sea on Tuesday.