At least 140 were killed and 160 people were wounded in the attack by Taliban terrorists on the Afghan military base, Mohammad Ibrahim Khair Andesh, the head of the provincial council, announced on Saturday.
The attack, responsibility for which was later claimed by the Taliban, happened at an army command centre a few miles from Mazar-e Sharif, the capital of Balkh.
Two of the attackers blew themselves up and seven were killed in the assault, which lasted several hours and targeted soldiers at a mosque and dining facility, the Afghan defence ministry said.
The Taliban claimed that more than 500 soldiers were killed and wounded, Al Jazeera reported.
The group also claimed that four of the attackers were soldiers who had served at the base and had knowledge of the facility.