Yonhap news agency reported Sunday police and rescue workers were trying to save four others still believed trapped in the landslide at the building construction site in Pangyo, south of Seoul.
Yonhap said the accident happened around 8:30 am when an H-shaped beam supporting a side of the 22-meter-deep, rectangular pit collapsed.
The report said about 150 rescue workers were using cranes and other equipment to save those believed trapped.
Conditions of those injured were not available.
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