At least eight people were killed and more than 20 others injured in a major fire at a chemical factory in the northern Indian state of Uttar Pradesh on Saturday, police said.

The fire broke out following a boiler explosion at the factory in the state’s Hapur district, some 80 kms from Delhi.

“Some 15 fire tenders have been pressed into service. So far, eight charred bodies have been recovered by the firefighters,” a police officer told the local media.

Hapur range inspector general of police Praveen Kumar said that the injured were admitted to a nearby hospital. “The condition of some of them are serious.”

State Chief Minister Yogi Adityanath took to Twitter to convey his condolences to the bereaved families.

“The chief minister has directed district administration officers to go to the spot and oversee rescue and relief measures and extend all possible help to the victims and their families,” his office tweeted.

“A probe has been ordered into the fire,” Kumar said.

Factory fires are common in India, and are often attributed to the absence of basic fire safety systems. A number of people die in such fires in India every year.