Police in the northern province of Quang Ninh arrested the owner of an illegal coal mine on Monday after three workers died of suffocation earlier the same day.
Tran Thanh Tuyen, 30, of Dong Trieu District will be detained for illegally exploiting coal, police said.
On Monday morning, Vu Van Bai, 33, Pham Van Tuan, 26, and Hoang Xuan Truong, 19, were found dead in the mine run by Tuyen.
Autopsies showed the trio died of asphyxiation.
Tuyen gave himself up to police Monday evening. He confessed to reopening an illegal coal mine that had previously been demolished by local authorities.
His coal mine lies within the boundary of a legal, larger mine run by the Hong Thai Coal Company in Trang Luong Commune.