No coalition forces were killed, but two were wounded, CNN reported. Four Afghan police officers, as well as a child and two women, were among the dead, Shahidullah Shahid, a spokesman for the Wardak province governor, said.
The first bomber walked up to the gate of the base in Saidabad and blew himself up, Shahid said. That opened the way for the second suicide bomber driving a truck.
Houses and a large portion of a local bazaar were destroyed in the blast, which was described as "massive," the BBC said.
The Taliban claimed responsibility for the attack.
An attack on the same base last year on the eve of the anniversary of the Sept. 11, 2001, attacks killed five Afghans and injured more than 80 people, including about 50 U.S. soldiers.