North Korea has vowed to cut two key communication hotlines with the South, amid rising tensions after Pyongyang’s recent rocket and nuclear tests.
It comes after Seoul suspended its operations at the jointly-run Kaesong industrial complex in the North.
Kaesong is one of the last points of co-operation between the two Koreas and a key source of revenue for Pyongyang.
The North has called the shutdown “a declaration of war” and has designated Kaesong as a military zone.
Seoul says the suspension is aimed at cutting off money the North uses for nuclear and missile development.
North Korea previously cut communication hotlines with the South in 2013, but reopened them after relations improved.
The hotlines, which are intended to defuse dangerous military situations, include one used by the military, and another used to communicate with the UN Command at Panmunjom in the Demilitarised Zone.
A third hotline is maintained by the Red Cross.
Yesterday, Pyongyang vowed to seize the assets of South Korean companies in Kaesong, and said all workers from the south had to leave by 17:30 local time.
South Korean companies had already started withdrawing managers, equipment and stock after Seoul announcement.