A Pakistani shop owner has confessed to killing at least 30 people by lacing traditional Pakistani sweets with pesticide in an act of revenge. Police told local media in the Punjab Province that around 52 people were affected by the tainted sweets in April, although some reports suggest there could be up to 70 victims.

Authorities say that 11 members of the same family died after eating the laddoos, a traditional Pakistani sweet. The tainted batch was purchased by a local man to serve at a party, celebrating the birth of his grandson.

The father of the baby was killed along with six of his uncles and one aunt. The AFP reported that five children are also among the dead and four victims remain in hospital.

Officials say that Khalid Mehmood, 18, confessed to putting pesticide in the sweets as revenge after his elder brother Tariq, who also owned the sweet shop, "insulted and abused" him over a business dispute, it is alleged.

District police officer Ramiz Bokhari said Mehmood accused his brother of abusing him. Bokhari told the BBC: "He told police his elder brother used to beat and abuse him", with the teenager poisoning the sweets "in anger and revenge".

Both of the Mehmood brothers and several of their employees were arrested after the incident. The pair are expected to appear in court in central Punjab province on Saturday 7 May. "I wanted to teach him a lesson," police investigator Mohammad Afzal was quoted as saying. "I was so angry that I mixed the pesticides bottle in the sweets being baked at that time."

Local reports suggest that more than one person has admitted the crime with the owner of a nearby pesticide shop telling police he had poisoned the sweets after a row with one of the sweet-shop owners.

To add to the confusion, an employee at the sweet shop has also confessed to accidently mixing the pesticide in the laddoos.