Fifteen people fell sick after eating food from a shop on Super Highway on Sunday.
SSP Malir said that the people belong to the same family. They have been shifted to a hospital.
He said that the family members had bought rice and food colouring for zarda (a sweet dish made with rice, food colouring, milk, and sugar).
The police have taken a sample of the rice and food colouring and send it for forensics.
The shopkeeper has been arrested and his shop has been sealed, said the police.