PESHAWAR: Three people were killed and another man was injured in firing on a car on Northern Bypass near Chamkani on Wednesday.A police official said Sardar, Mansoor and Kaptan were killed and Naveed was injured when armed men opened fire on their car in Chamkani.The victims belonged to Charsadda.Police said the deceased had an old enmity and the rivals were believed to be behind the attack.A case was registered.