AlQa'dah 16, 1432, Oct 14, 2011, SPA -- A suicide attacker blew up an explosives-packed car Friday while it was being inspected at a border police checkpoint that had been set up in southern Afghanistan because of a warning of an imminent attack. Three officers were killed, as AP reported. The explosion happened in Spin Boldak, near the Pakistani border, in the early evening, said Gen. Abdul Raziq, the head of the border police in the south. Three officers and a civilian were wounded, he said. The checkpoint had been set up because of an intelligence warning that an attack was imminent, provincial government spokesman Zalmai Ayubi said. In the increasingly violent north, meanwhile, NATO and Afghan forces killed 13 insurgents in an overnight operation targeting local Taliban leaders.