The explosion occurred as a tractor pulling a trailer passed by. The dead all civilians include four women and two children. No group has so far claimed responsibility for the blast.
Taliban militants are active in Zabul, a sparsely populated region bordering on Pakistan, freely moving between the porous border.
Zabul was also the focus of other attacks when early on Monday two Taliban militants were killed as the bomb they were trying to plant accidently detonated.
And later on, Taliban militants attacked a group of construction workers, who were repairing a bridge, damaged in an earlier attack. Six security guards, who tried to protect the workers along with two passers-by, were killed as a result.
In addition, militants blew up a convoy escorting the mayor of Mihtarlam, the provincial capital of the Laghman province, in eastern Afghanistan. The official, his three bodyguards, a driver and four passers-by were killed in the explosion.
