A planted bomb that targeted a police van killed four policemen and a child. The police van was carrying more than 20 policemen and there were school boys at the site, when the blast occurred. The blast occurred in a major city, after a long pause. It is appreciable that the law enforcement agencies have so far been successful in controlling the terrorist elements and have restricted them to a few areas as well. Exerting a complete control over terrorists will require cooperation from the local people, particularly those who support and give refuge to terrorists. Terrorism is our collective problem, and everyone must play a positive role in identifying criminal and terrorists elements around them. ZULFIQAR HAIDER, Islamabad, August 11.