Four people including a woman killed while two others injured in the ongoing wave of target killing in Karachi on Monday, a private TV reported. Some unidentified miscreants gunned down a political activist Umar Ali of Pirabad, while in Nazimabad 4 motorcyclists mowed down a youth. Driver of Agha Khan Hospital was killed near Teen Hatti area, whereas 25-year-old Nasreen was killed when some unknown miscreants opened indiscriminate firing at a bus stop of Lal Shahbaz Colony.