The Taliban quickly asserted responsibility for the attack, which takes the number 10.
Abdul Jabar Qahraman had a meeting with supporters in his campaign office in the southern province of Helmand ̵
Qashaman killed by the blast in the provincial capital Lashkar Gah, interior minister Wais Ahmad Barmak told reporters.
President Ashraf Ghani condemned the attack on Qatar, who was sent to Helmand in 2016 as an envoy to help defeat the Taliban. Qahraman later resigned.
In other poll-related violence, ambushed a candidate's convoy in Logar province, near Kabul, on Wednesday, provincial governor spokesman Shamshad Laraway said.
And later an improvised explosive device blew up near the campaign Pule Alam, Laraway said.
There were no casualties in either attack.
Official campaigning for the ballot ends at midnight Wednesday.
Most of the 10 candidates who have died
Qahraman was killed in a suicide attack last week.
That incident, after Saleh Mohammad Asikzai died The Taliban issued a fresh warning on Wednesday, June 10, 2010 The Taliban warned candidates to withdraw from the parliamentary election.
Violence has overtaken people with long-delayed vote, with hundreds of people killed or wounded in poll-related attacks across the country
Preparations for the Ballot have been completed in shambles and are now in the process of being released,  [more]
The election for parliament's lower house is a dry run
It will also be seen as a key milestone ahead of a UN meeting at Geneva in November, where Afghanistan wants to "see"
Almost nine million people have registered to vote, but observers expect far fewer to turn out due to the threat of militant attacks and expectations of widespread fraud.  strs-emh-us-amj / ds / jta
More than 50,000 members of Afghanistan's already overstretched security forces are deployed to protect themselves from polling centers.
Afghanistan's long-delayed parliamentary election
Map of Afghanistan showing severity of conflict in 2017, according to UN Office for the Coordination of Humanitarian Affairs.