HERAT, Afghanistan (Reuters) - Armed men have killed five campaigners working for a female candidate in next month's parliamentary election in Afghanistan, an official said on Sunday, the latest attack amid growing security fears.
The election is being seen as a key test of stability in Afghanistan, where violence is at its worst since the Taliban were ousted in 2001, before U.S. President Barack Obama conducts a review of his Afghan war strategy in December.
Poor security, particularly in Taliban strongholds in the south and east, already looms as the biggest challenge to the ballot, along with corruption and fraud.
Four candidates have already been killed. On Saturday, unidentified gunmen killed candidate Haji Abdul Manan as he walked from his home to a mosque in western Herat province. The Taliban later claimed the attack.
Last Thursday, up to 10 campaign workers for outspoken female candidate Fawzia Gilani went missing in Herat's Adraskan district.
Officials originally said it was not known if they had been abducted by the Taliban or political rivals, although a spokesman for the Islamist militants later said the Taliban had seized five of them.
Five of those taken later turned up unharmed.
The district chief of Adraskan said the bullet-riddled bodies of the other five were found on a hillside in Adraskan, but added it was still not clear who killed them.
"We have sent the bodies to hospital," district chief Nisar Ahmad Popal told Reuters.
The Taliban could not be reached for comment immediately.
The United Nations, which helped oversee last year's fraud-marred presidential vote, said two weeks ago three candidates had been killed and that widespread intimidation of female candidates and other instances of election violence had been observed.
It described such incidents as "unacceptable" and called on Afghan security forces to maintain heightened vigilance.
About 2,500 candidates are contesting the ballot for 249 seats in the wolesi jirga, the lower house of parliament.
Election officials said this month that more than 900 of 6,835 planned polling centers would not open because of poor security.
The Taliban tried, with limited success, to disrupt a 2005 parliamentary vote and last year's presidential vote but insurgents so far have made no direct threats against the poll.
Of the 249 seats, 65 are set aside for women and there are about 385 female candidates.
(Reporting by Sharafuddin Sharafyar; Writing by Sayed Salahuddin; Editing by Paul Tait)