Klang Utara police chief S Vijaya Rao said investigations revealed that the incident was caused by a chemical reaction.

“The police have finished taking statements from the factory owner, workers, and witnesses.

“We were also informed that clean-up efforts are ongoing at the factory,” he told reporters during a visit to the Taman Eng Ann morning market, Bernama reported.

He said further investigations by the department of environment and department of occupational safety and health are ongoing.

Last Tuesday, Vijaya confirmed that 32 people who were in the vicinity were injured in the explosion.

He said they were given outpatient treatment at Tunku Ampuan Rahimah Hospital and allowed to return home.

The Selangor fire and rescue department said a hazmat team had found that the chemicals were recycled acid.

Commenting on another fire at a liquefied petroleum gas factory in the Sungai Puloh industrial area, Vijaya confirmed that a second victim had died of his injuries.

“The foreign worker passed away a day after the first victim due to severe burn injuries. This case is being investigated as a sudden death,” he said.