The radical Islamic Taliban have probably penetrated into the Afghan capital Kabul.
The Interior Ministry announced that the Islamists were advancing from all sides.
Residents of the outskirts of the capital also told the AFP news agency on Sunday morning that Islamist fighters were in the city.
A Taliban spokesman said the fighters had orders to stop at the city gates and not to advance into Kabul.
Rather, they should take a stand at the gates of the city, according to a statement by the Islamists published on Sunday.
Since the capital Kabul is a large and densely populated city, the Taliban did not intend to enter the city by force or war.
Rather, they want to negotiate a peaceful invasion of Kabul with the other side.
Shortly before, the Taliban had also taken the penultimate city, Jalalabad in eastern Afghanistan.
Like Mazar-i-Sharif, it was left to the fighters without resistance.
"There is currently no fighting because the governor has surrendered to the Taliban," said an Afghan official told Reuters.
This was the only way to save civilians' lives.