A Taiwanese-owned metal factory in Kunshan, China, where at least 75 people were killed in an explosion Saturday, ignored several warnings from local safety regulators and what workers say were dangerously dusty working conditions, according to a report by the South China Morning Post.

The explosion at the Kunshan Zhongrong Metal Products Company, in southeastern China, is thought to have been caused by a naked flame in a dust-filled workshop used to polish automobile wheel hubs. DNA tests were reportedly needed to identify the dead, the report said, adding that the explosion injured at least 186 workers, many of whom suffered serious burns and were sent to the neighboring cities of Shanghai, Suzhou, Nantong and Wuxi for treatment.

"Each time I went to that room there was dust everywhere: on the ground, on workers' faces and on their clothes,” said Wu Ming, 45, who has worked for seven years at a sand-blasting workshop, which was close to where the blast occurred, and added that the car-parts factory was infamous among migrant workers for its “dirty environment but high wages.”

Wu, who helped retrieve bodies after the blast, reportedly said that employees had to work for at least 12 hours a day for about $800 a month.

"Workers in that workshop told me they knew it was a dangerous job and it was bad for their health, but they had to earn money for their kids," he reportedly said.

A former employee who worked at the factory in 2006 told SCMP: "We knew the dust would hurt our throats and there was a risk of an explosion, but we had no choice and we needed more money."

Five factory officials have reportedly been detained by the police in connection with the incident.