BEIJING (AP) — Investigators said that sparks from welding work appears to have been the cause of a fire that killed 38 people at a company dealing in chemicals and other industrial goods in central China’s Henan province.

Two other people were injured in the blaze that tore through the building in the city of Anyang starting at about 4:30 p.m. Monday. It took firefighters about 3 1/2 hours to bring the flames under control, the Wenfang district government said.

One or more welders operating in violation of safety rules appear to have let loose sparks that ignited cotton fabric in the building, according to officials cited by the official Xinhua News Agency. The investigation was ongoing, with company managers and local government officials being questioned, Xinhua said.

China has a history of industrial accidents caused by lax regard to safety measures fueled by rising competition and abetted by corruption among officials.

Online listings for the company, Kaixinda, said it wholesaled in a wide range of industrial goods including chemicals.

Video footage on state broadcaster CCTV showed flames and smoke billowing out of what appeared to be a two-story building engulfed in fire. In nighttime shots, firefighters examined the scarred, skeletal remains of the structure with an extension ladder and lights.

More than 250 firefighters and rescue workers were deployed, according to the statement.

Henan, a densely-populated and economically vital province, has seen a number of recent deadly incidents leading to the arrest of local officials.

Five were arrested after a building collapse that killed 53 people on the outskirts of the provincial capital Changsha in April.

The central government has pledged stronger measures ever since a massive 2015 explosion at a chemical warehouse in the northern port city of Tianjin killed 173 people, most of them firefighters and police officers. The chemicals were found to be falsely registered and stored, with local officials found complicit in turning a blind eye to the potential threat.