"North Korea conducted GPS jamming provocations in Haeju and Kaesong yesterday and today," Seoul's joint chiefs of staff (JCS) said in a statement Saturday, adding several vessels and dozens of civilian aircraft were experiencing "some operational disruptions".

The military also warned ships and aircraft operating in the Yellow Sea to beware of such attacks. According to the JCS, military operations and equipment were not affected.

A similar jamming attack had previously occurred on November 5. A JCS official noted that this week’s GPS jamming attacks are weaker compared to those in May and June.