South Korean news agency Yonhap says that the 53,000 North Korean workers employed in the Kaesong industrial complex jointly run by the two Koreas just north of their common border did not show up for work on April 5.
Yonhap quoted the South's Unification Ministry as saying that the operations were halted in observance of North Korea's Arbor Day holiday.
The holiday was declared a day off for the first time in North Korea this year.
Pyongyang has barred traffic from South Korea into the complex since April 3, only allowing workers to leave, while the South has said it is ready to withdraw all its workers from Kaesong.
Tensions on the Korean peninsula are growing with South Korea and its ally the United States beefing up defenses after Pyongyang issued threats, including a vow to launch a possible nuclear strike.
Based on reporting AP, AFP, and dpa