North Korea threatened to shut down a border industrial zone it jointly operates with South Korea just a day after Pyongyang declared a “state of war” in the Korean peninsula.

The Kaesong Industrial Complex, which stands as the last significant symbol of inter-Korean cooperation, will be “mercilessly shut down” unless South Korea stops “damaging our dignity”, the official KCNA news agency on Saturday quoted an agency in charge of the complex as saying. On Monday, South Korean workers entered Kaesong as usual.

The threat came as a response to perceived insults that the industrial park was only being kept to raise money for the impoverished North.

The eight-year-old industrial park funnels more than $92 million a year in wages for 53,400 North Koreans employed in over 100 South Korean factories operating there.

While the shutdown will likely affect South Korea, the losses would be restricted to the companies operating in the complex, whereas the North Korean regime would suffer a graver impact, reports Chosun Ilbo.

An unnamed North Korean spokesman for the complex dismissed that the North was benefiting from the joint venture or that its closure would bankrupt the South Korean manufacturers.

North Korea has ramped up its nuclear war rhetoric since South Korea and the United States started a joint military exercise in early March.