The Taliban overran the Tirgaran base in the northeastern province of Badakhshan, which borders China, Pakistan and Tajikistan. The policeman were forced to surrender, but were freed after handing over their weapons.
"The enemy got weapons and ammunition from police forces at the Tirgaran base that will allow them to fight for a long time," provincial governor Shah Waliullah Adib told Reuters. "We will launch an operation soon and take back control of the base."
The surrender was the largest by Afghan security forces since NATO ended its combat mission in December, the BBC reported.
Some police officials blamed the Afghan government for failing to send reinforcements.
Government officials said army commandos were on their way when the policemen surrendered the base. Poor weather prevented reinforcements from arriving earlier.
"They had sufficient resources. They were being impatient," Shahwaliullah Adeeb, the governor of Badakhshan, was quoted as saying by the Wall Street Journal.
The Taliban attacked the base two days earlier with the help of an Afghan local police commander, according to two senior Afghan security officials. The commander, known as Mullah Jalal, had surrendered earlier along with his 40 men.
"He pretended to fight the Taliban but instead he surrendered," one official told the WSJ. "Then Jalal came back to the base to strike a deal with the remaining forces on behalf of the Taliban."
By capturing the base, the Taliban have pushed closer to a strategic crossing at Pakistani border. The victory may be the group's greatest advance in Badakhshan since being ousted from power in 2001, according to a Western security report obtained by Reuters.
"If successful, they [Taliban] will be able to establish a corridor… facilitating the cross-border movement of fighters currently based in Pakistan," the report said.