At least four farmers have been killed and four others were wounded after the Madhya Pradesh Police opened fire in an attempt to control a rioting mob demanding fair price and loan waiver in Mandsaur district on Tuesday.

The police resorted to firing to gain control on the agitating farmers after their protests turned violent as they allegedly set ablaze at least 10 trucks, one Dial 100 vehicle and three motorcycles in Pipliamandi area.