KABUL, Afghanistan - The death toll from a suicide bombing at an Afghan police headquarters rose by one to 13 on Sunday after men disguised as officers made it through three security gates before detonating their explosives.

Afghan officials launched an investigation into the attack on Saturday in eastern Afghanistan. All those killed were policemen.

Senior Deputy Interior Minister Gen Abdul Rahman Rahman led a delegation to Paktika Province, where the twin blasts struck the police headquarters within 20 minutes of each, said Zemari Bashary, a spokesman for the Interior Ministry. Thirteen officers were killed and 14 were wounded, he said.