(CNN) -- The last seven South Koreans who remained at a manufacturing complex jointly run by North and South Korea left the area Friday -- further crumbling one of the few symbols of inter-Korean cooperation amid high tensions between the nations.
The workers left the Kaesong Industrial Complex in North Korea and returned to the South, the South Korean Unification Ministry said. This marks the first time in the facility's nine-year history that no South Korean workers are there.
South Korean broadcaster YTN, a CNN affiliate, showed video of the South Koreans' vehicles, with luggage tied on top, re-entering the South.
The move caps a monthlong winding down of operations at the complex, which the North suspended during a frenzy of rhetoric aimed at South Korea and the United States last month. The North's rhetoric intensified after the U.N. Security Council voted in March to slap tougher sanctions on the regime and amid U.S.-South Korean military drills in the region.
The complex, which sits just north of the Demilitarized Zone that separates the two countries, houses the operations of more than 120 South Korean companies.
One of the seven returning South Koreans, Hong Yang-ho, chairman of Kaesong Industrial District Management Committee, said his panel is urging North Korea to reopen the complex as soon as possible "so as to minimize damages (to) relevant companies."
"We hope there will be further negotiations through various channels," he said Friday.
The North began blocking South Koreans from entering the complex across the heavily fortified border in April. It then pulled out more than 50,000 North Koreans who work in the zone's factories, saying it was temporarily suspending activity there.
The move surprised some observers since Kaesong was considered a key source of hard currency for the Kim Jong Un regime.
Last week, South Korea started withdrawing its remaining citizens from the manufacturing zone jointly operated with the North. The seven South Koreans who returned Friday had remained at Kaesong to tie up loose ends.
It isn't the first time Kaesong has shut down.
In 2009, North Korea temporarily suspended Kaesong Industrial Complex several times, not permitting South Koreans to enter and exit the zone. The suspension also took place during the annual U.S.-South Korean joint military drill. But that time, South Koreans still remained at the complex.
In 2012, the production value of the complex grew to $500 million; five years earlier, it topped $100 million for the first time.
The average wage for North Korean workers in Kaesong Industrial Complex is $134 per month, according to the South Korean Unification Ministry. North Korean authorities take about 45% of their wages for various tax reasons.