South Korean protesters burn an effigy of North Korea leader Kim Jong-Un during an anti-North Korea rally on February 11, 2016 in Seoul, South Korea. South Korea announced that it would close an industrial complex jointly ran with North Korea.

Story highlights

280 workers based in the North have arrived back in South Korea, Unification Ministry says

Pyongyang reacted angrily to the South Korean decision to shut down the industrial complex

Kaesong represents a rare example of cooperation between the two neighbors

CNN  — 

Hundreds of workers from South Korea have been repatriated from an industrial complex in North Korea just north of the border separating the two Koreas.

The South Korean Unification Ministry said Thursday that 280 workers who had been stationed at the Kaesong industrial complex had crossed the military demarcation line and were back on South Korean soil.

Electric power to Kaesong, which had been provided by South Korea, has also been cut, along with its water supply.

The repatriation of its workers comes after the South announced it would be closing the complex following North Korea’s recent rocket launch and nuclear test, and shortly after it emerged that Kim Jong Un’s regime had executed a top military official, Ri Yong Gil.

The park, which opened in 2004, is a rare of example of cooperation between the two countries and has been a key diplomatic initiative between them.

More than 120 South Korean companies have a presence there, employing tens of thousands of North Koreans and providing an important stream of hard currency to Pyongyang.

The U.S. Senate has voted to tighten sanctions on North Korea, while Japan has also announced new sanctions on the Stalinist nation.

In response to a possible North Korean missile threat, South Korean and U.S. officials will hold discussions on the deployment of the THAAD (Terminal High Altitude Area Defense) missile defense system as early as next week.

China, North Korea’s sole ally in the region, has expressed its reservations about the deployment of the advanced U.S.-built system on the Korean peninsula, which it worries could be used against its own launch systems.

A vehicle leaving the Kaesong joint industrial zone passes through disinfectant spray before a checkpoint at the CIQ immigration centre near the Demilitarized Zone (DMZ) separating North an South Korea, in Paju on February 11, 2016.

Angry reaction

In the wake of South Korea’s decision to shut the plant, Pyongyang announced Thursday that it would expel all South Koreans from the facility and freeze all assets there.

It likened Seoul’s decision to close the facility to “dropping an ax on one’s own foot.”

“This provocative measure cuts off the last existing lifeline between North and South Korean relations … and is a very dangerous declaration that drives the situation on the Korean peninsula to the furthest extreme of confrontation and war,” North Korean state media reported, quoting a government committee.

The statement said it was “unpardonable” of Seoul to find fault with Pyongyang’s recent rocket launch and nuclear test, actions it said were “a just measure for self defense and an exercise of its legitimate right.”

The two Koreas have technically been at war since hostilities began in 1950. An armistice was signed in 1953.

In 2013, the North declared the ceasefire agreement invalid, just one of many tit-for-tat moves by the North on this divided peninsula.

READ MORE: North and South Korea’s Kaesong complex shaken by pay dispute

CNN’s Paula Hancocks in Seoul and Tim Hume in London contributed to this report.