At least 41 people have died after drinking tainted liquor in a slum in India’s financial hub of Mumbai, police said Friday, the Associated Press reports.

Police officer Deepak Gaikwad said 21 other people were hospitalized in critical condition after drinking the cheap liquor in Malad in northern Mumbai.

Police arrested three men and were questioning them about making and selling the drink to poor workers.

Devendra Fadnavis, the top elected official in Maharashtra state, where Mumbai is the capital, ordered an investigation.

Deaths from illegally brewed alcohol are common in India because the poor cannot afford licensed liquor. Illicit liquor is often spiked with chemicals such as pesticides to increase its potency.