At least six people were killed and several others injured in separate incidents of firing in Pakistan\'s southern port city of Karachi on Friday, local media and Police said. The incidents of violence broke out early in the morning where two people were gunned down in Haji Camp area of the city, stirring tension in the area. Later, two bodies with eminent marks of torture were found from the Nazimabad area. Two men were killed and several others injured in separate incidents of firing by unknown motor-cyclists in Abul Hassan Isphahani Road and New Mianwali areas of the city. Commercial and educational activities halted in the affected areas and residents demanded deployment of more police force in the area. The history of violence in Karachi dates back to early 1990\'s but the situation became uncontrollable since the last two years, mainly because of the increasing sectarian, ethnic and political clashes in the city that is home to over 21 million people. According to Karachi police, over 2,000 people have been shot down in the city since the beginning of 2012. Police is conducting search operations in various areas of the city to apprehend the people involved in deteriorating law and order situation of Karachi. Earlier last week, the Sindh Police chief said that 165 target killers have been arrested by police since the beginning of this year, and they are hopeful to apprehend more killers by information provided by the arrested convicts. Addressing a session of Senate on Nov. 19, Interior Minister Rehman Malik said that an estimated 2,339 police encounters have been reported in 2012, in which 145 armed bandits and over 100 policemen were killed.