North Korea says a decision by the South to suspend operations in a shared industrial zone is a declaration of war.

The North has ordered South Koreans to get out of the industrial area immediately, and frozen the assets of companies operating there.

South Korea was already in the process of shutting down its operations in Kaesong industrial park following last week's missile launch by the North.

More than a hundred South Korean companies operate in the area, employing thousands of people from the North.