A roadside bomb ripped through a Pakistani security forces' convoy, killing five policemen and an army officer in a northwest town, officials said Friday. The bomb exploded Thursday near the town of Mardan , the area where many of the two million people have fled after being displaced by Pakistan's military offensive against the Taliban. "An army captain and five police officials were killed when a remote-controlled device planted on the road exploded," a senior military official said. Local police chief Waqif Khan confirmed the death toll, saying it had been a police convoy escorted by an army vehicle. The device carried about 30 kilogrammes of explosives. Officials had said initially Thursday that 22 policemen were wounded.