The ambush took place on Wednesday in the Wurduj district of Badakshan province. The Taliban claimed responsibility after the attack.
The ministry statement also said 47 insurgents were killed in the same area during a police operation earlier in the week.
Although attacks with high casualty figures are increasingly common as insurgents escalate their campaign against government forces across Afghanistan, they are rare in Badakshan.
The region, nestled in the Hindu Kush and Pamir mountain ranges and bordering China, is one of the most remote in the country.
Casualties among Afghan security forces have been increasing after they took over the lead for security around the country from foreign troops earlier this summer.
The NATO-led international coalition has been steadily drawing down and foreign forces are no longer leading the fight against the insurgency, but are instead training and assisting Afghans.
All foreign combat forces are to leave Afghanistan by the end of 2014, possibly to be replaced by a smaller group of trainers.
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