South Korea warned Pyongyang not to damage its equipment at the Kaesong industrial zone, a jointly run complex that was shut down this week amid rising tensions between the two sides, a news report said Friday.
North Korea said Thursday it would seize machinery and manufactured goods at Kaesong in response to the South's decision to order all its citizens home from the site.
Along with a North Korean move to switch off both its high-level telephone hotlines to the South, the closure of their main point of business exchange reflects the bitterness between the two governments since a nuclear test and a long-range rocket launch by Pyongyang in the last six weeks.
Seoul's Unification Minister Hong Yong Pyo said Pyongyang "should take all responsibility for what will happen from now on," and warned against any damage to assets at the site, Yonhap News Agency reported.
South Korean firms hit by the shutdown would be offered state support, he told a news conference.
The Kaesong factory estate, only a few kilometres north of the heavily militarized border, served as a window to the outside world for the reclusive, communist North and earned scarce foreign currency for Pyongyang.
Some 54,000 low-paid North Koreans work in more than 124 factories, which produce textiles, clothes, household appliances and parts for machines, cars and semiconductors.