The six men were seized late Saturday while traveling back to their base after a day working on a road construction project, according to Abdul Sattar Barez, the deputy provincial governor of Faryab province.
Nobody has claimed responsibility for the kidnapping. Afghan police and intelligence services were searching for the men.
Kidnappings - mostly of Afghans - for ransom or for political reasons are on common in Afghanistan, where violence has made efforts to rebuild the country costly and dangerous.
Saturday's abduction occurred in Faryab province, which sits on the border with Turkmenistan and has been relatively peaceful since the 2001 US invasion that unseated the Taliban's hard-line Islamist rule.