Law-enforcers carried out a search operation in Afghan Basti at Sohrab Goth here and rounded up 28 alleged miscreants, most of them Afghan nationals, and seized arms and ammunition from their possession. Officials say that two proclaimed offenders, who are wanted in several criminal cases including murder, are among those detained. An official said that the arrested suspects did not belong to any political party and had allegedly taken advantage of recent wave of violence in the city. Security has been beefed up in this southern port city of Pakistan, which is still reeling from a three-day violence spree unleashed by unknown elements. In what could best be described as a pre-emptive move on the directives from the federal government, the provincial authorities have decided to launch a weapon recovery campaign and a search operation against miscreants and terrorist elements in Karachi. The preliminary operation kicked off from Sohrab Goth, one of the most sensitive areas of the city, in which heavy contingents of police and Rangers along with dozens of mobile vans and armored vehicles took part.