The seven escaped on 22 January from the Pul-e Charkhi prison, authorities said.
The prison's governor, Abdul Salam Bakhshi, said 10 guards are being investigated for possible involvement in the escape.
Bakhshi declined to identify any of the escaped prisoners. He said security forces are hunting for them.
In July, four prisoners escaped from the main U.S. military prison in Afghanistan.
A standoff at Pul-e Charkhi and the ensuing raid by Afghan National Army forces left eight people dead in December 2004, after an attempted prison escape turned into a riot.