At least 20 others were wounded in the the Saturday night attack on the base in Ghormach district, provincial council members Abdul Manan Qatay and Abdul Ahad Elbeik, told dpa.
Qatay said that security posts on top of a mountain overlooking the base had fallen to the Taliban as well, making the military facility vulnerable to the attack.
The base itself is currently under army control, Qatay added.
The base had been surrounded by Taliban for months with little help from the provincial capital, according to both council members.
Qatay and Elbeik said that the connecting road from the provincial capital Maimana to the district had been closed by the Taliban, making it difficult to get ground support into the area.