Gurpreet Singh alias GopiCHANIGARH: An Aam Aadmi Party (AAP) leader, Gurpreet Singh alias Gopi, was shot dead by four armed assailants in Punjab's Mamdot, police said on Sunday.According to news agency PTI, the 45-year-old was travelling in a car with another man, identified as Harpreet alias Happy, 22, when the attackers opened fire on them in the town's main bazaar on Saturday evening.According to police, the four assailants arrived in a car, got out of the vehicle and opened fire at Singh's car.Singh and Harpreet were taken to the Civil Hospital after the shooting. Doctors declared Singh dead on arrival.Harpreet, who was injured in the attack, was referred to a private hospital in Ludhiana for further treatment.Police are investigating the circumstances surrounding the shooting and are trying to identify the attackers.(With PTI inputs)