KABUL, Afghanistan — Officials say a twin bombing in southern Afghanistan has killed five people, three civilians whose car struck a roadside bomb and two police officers who had rushed to the scene to help the victims when the second bomb went off.

A provincial government spokesman, Ummar Zawaq, says the attack occurred on Thursday morning in Helmand province.

Zawaq says the officers who died were members of the elite Afghan National Civil Order Police — the so-called ANCOPs who get special training from NATO forces.

The spokesman says a third officer was wounded in the blast.

Afghan authorities say roadside bombs and booby-traps are their worst threat in fighting the Taliban.