Over 250 law enforcers have been killed and many injured in Pakistan's city of Karachi over the last two years, officials said.At a press conference in Karachi on Saturday, officials said that in the operation against militancy and street crimes launched on September 5, 2013 in the city, 232 policemen and 27 troopers have died, Xinhua reported."The law enforcement agencies have killed 282 militants, arrested 38 kidnappers and 10 extortionists. They have also recovered 15,400 weapons, bullet-proof jackets, rocket launchers and grenades during the operation," Additional Inspector General Police Mushtaq Maher said.He said terror-related incidents have been reduced by up to 60 percent, target killing reduced by up to 70 percent and extortion had come down up to 60 percent since the commencement of the operation.The Karachi operation was initiated on the directives of the federal government four months after Prime Minister Nawaz Sharif was sworn in.