Five labourers were killed and at least nine were injured after a boiler exploded at the Sasa Musa Sugar Mill in Bihar’s Gopalganj district on Wednesday night.

“Five bodies have been recovered from the site of the incident,” Awadhesh Kumar, station house officer of the Kuchaykot Police Station, told PTI, adding that they could not identity one of the bodies.

Local residents said they heard a loud blast around 11.35 pm on Wednesday, the Hindustan Times reported. The police have detained the sugar mill owner, Mahmood Ali and his two sons.

At least 100 workers were present at the site when the boiler exploded, News18 reported. Nine workers sustained 90% burn injuries and are undergoing treated, Gopalganj District Hospital Superintendent Shashikant Mishra told the news channel.

Soon after, angry workers set vehicles inside the premises on fire.

Chief Minister Nitish Kumar announced compensation amount of Rs 4 lakh for the families of the victims of the blast. He also ordered a high-level inquiry into the incident, PTI reported.

The incident comes a month after a massive explosion at the state-run NTPC’s Unchahar thermal power plant in Uttar Pradesh’s Rae Bareli district claimed 32 lives. More than 100 people were injured. According to an investigation carried out by the Uttar Pradesh labour department, sheer negligence on part of the NTPC plant was the reason behind the November 1 explosion.