Two of the attackers blew themselves up and seven were killed in the assault near Mazar-i-Sharif city on Friday which lasted several hours and targeted soldiers at a mosque and dining facility.
“The majority of our soldiers were offering Friday prayers” at the time of the assault, the ministry said in a statement, adding that “over 100 Afghan army forces were martyred and wounded”.
The government toll of the attack came as a military official who was at the base at the time of the assault told AFP that “150 soldiers were killed and dozens wounded”.
“They were young recruits who had come for training,” he said on condition of anonymity.
A US military spokesman said earlier that “more than 50” Afghan soldiers were killed in the attack claimed by the Taliban, while Afghan officials had initially put the death toll at eight with 11 wounded.
The latest deadly assault against an Afghan military site underscores rising insecurity in the war-torn country as it braces for an intense fighting season in the spring.
The facility in Balkh province is home to the Afghan army’s 209th Corps.
The last major attack against a military site was in early March when gunmen disguised as doctors stormed the Sardar Daud Khan hospital — the country’s largest military hospital — in Kabul, killing dozens.