Five members of female politician's campaign team abducted and killed

(AP)

Armed men have killed five campaigners working for a female candidate in next month's parliamentary election in Afghanistan.

Last Thursday, up to 10 campaign workers for the 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 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. The Taliban could not be reached for comment.

The UN said two weeks ago that three candidates had been killed, and that widespread intimidation of female candidates and other instances of election violence had been observed. 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.

Poor security, particularly in Taliban strongholds in the south and east, already looms as the biggest challenge to the ballot. 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.