KABUL, Afghanistan, Rajab 16, 1432, Jun 18, 2011, SPA - An Afghan police chief says two separate roadside bomb attacks have killed four private security guards escorting supply convoys traveling to a NATO base in eastern Afghanistan. Provincial police chief Mohammed Hussain said the attacks took place early Saturday morning in Ghazni province. Hussain says those killed were Afghans working for security contractors. The two bombings happened within two hours of each other, the Associated Press reported. --SPA 11:23 LOCAL TIME 08:23 GMT www.spa.gov.sa/903354