SANTO DOMINGO, Dominican Republic (AP) — Three people were arrested Wednesday in the Dominican Republic as part of an ongoing investigation into a powerful explosion at a plastics company that killed at least 34 people earlier this month.

Those arrested include the owner of the company and his wife, a government official who was not authorized to speak to the media told The Associated Press.

The explosion was caused by an accumulation of highly flammable gases that could have been generated by the plastics and organic peroxide material stored at the company, according to a preliminary report by the firefighting department obtained by the AP.

The company, Vidal Plast, recycles, sells and buys plastic material.

Authorities previously said they have evidence that there was a fire at the business in March caused by a spark and a chemical substance, and that the company did not take any measures “despite knowing the high risk of its operations.”

Norberto Rondón, the attorney of those arrested, told reporters Wednesday that the company had been shuttered since May and accused the country’s firefighting department of issuing a preliminary report of “lies and half-truths.”

It is the first time someone is arrested in the case, with authorities still identifying victims, while another 60 people are recovering from injuries.

The Aug. 14 explosion occurred in a bustling commercial center in the city of San Cristobal, just west of the capital, Santo Domingo. It took firefighters three days to extinguish the blaze.