A Pakistani candy shop owner has confessed to fatally poisoning at least 30 people by lacing his goods with pesticide in an attempt to take revenge on his older brother, police told AFP Friday.

Khalid Mehmood confessed in a court in central Punjab province that he had poisoned the candy after his elder brother Tariq, who owned the candy shop with him, “insulted and abused” him in a business dispute.

“I wanted to teach him a lesson,” police investigator Mohammad Afzal quoted him as saying, with the statement confirmed by another senior police official.

“I was so angry that I mixed the pesticides bottle in the sweets being baked at that time.”

The poisoned batch of candy were bought by a local man who gave them to family and friends celebrating the birth of his grandson.