A GPS signal screen is seen in this undated file photo, provided by the county of Onjin in Incheon. Yonhap

North Korea staged GPS jamming attacks for the second consecutive day Saturday, affecting several ships and dozens of civilian aircraft, according to South Korea's military.

The jamming attacks were conducted in the North's Haeju and Kaesong areas, the Joint Chiefs of Staff (JCS) said, warning vessels and civilian aircraft operating in the Yellow Sea to beware of the attacks.

Military operations and equipment were not affected, according to the JCS.

"North Korea should immediately halt the GPS provocation," the JCS said, warning it will be held accountable for its actions.

The latest threat came three days after the South's military detected a similar movement Tuesday.

The GPS jamming attacks this week, however, involved a weaker signal compared with the multiple attacks the North conducted near the northwestern border areas between May 29 and June 2, according to a JCS official.

In June, South Korea raised the North's repeated GPS jamming with three relevant international agencies — the International Telecommunication Union (ITU), the International Civil Aviation Organization (ICAO) and the International Maritime Organization (IMO) — requesting due measures to be taken for the provocations.

North Korea is a member of the ITU, ICAO and IMO.

In response, the ICAO adopted a decision raising serious concerns over North Korea's recent jamming of GPS navigation signals, specifying the North by its name for the first time. (Yonhap)