Islamabad, Jumada Al-Awwal 02, 1432, April 06, 2011, SPA -- Four children were killed and two wounded in a bomb explosion today in the close vicinity of the city of Kohat, North-Western Pakistan. The security sources said that someone anonymously left a bomb inside a bag near the square where the village children play, pointing out that the bomb exploded, killing two children immediately after the blast and injuring four others including two who died after being transported to the hospital. The sources said that security forces cordoned off the blast site and launched a wide-range sweep operation to search for the person responsible for detonating the bomb. --SPA 14:04 LOCAL TIME 11:04 GMT www.spa.gov.sa/881048