A suicide bomber on a motorcycle has killed the deputy governor of Afghanistan's Ghazni province, Mohammad Kazim Allahyar, his son and two bodyguards who were in the same car, a top police official said.
Two civilians passing by on a bicycle were also killed.
Delawar Zahid, police chief of Ghazni province, which lies around two hours' drive southwest of the capital Kabul, said that the men were near the airport in Ghazni city when the bomber struck.
"Allahyar was on his way to work when a suicide bomber on a motorbike targeted his car," Mr Zahid said.
"Allahyar, his son and two bodyguards were martyred."
His nephew and a third bodyguard were wounded and died in hospital, Mr Zahid said.
Suicide bomb attacks frequently kill civilians, bodyguards and members of the security forces, and insurgents sometimes execute low-level government officials, but it is relatively rare for them to hit high-level targets.
The most recent comparable attack was in eastern Laghman province in September last year when a suicide bomber killed Afghanistan's deputy head of intelligence and at least 22 others, according to the head of the counter-terrorism department in Kabul, Abdul Ghafar Sayedzada.
Ghazni is southwest of Kabul and has seen a steady increase in Taliban activity over recent years.
This year has been the bloodiest in Afghanistan since the Taliban's removal in 2001, with the militants making a comeback despite the presence of almost 150,000 foreign troops.
Reuters