Amin said the bomber detonated his explosive device at a checkpoint "after being identified by police".
Among the dead were two policemen, he said.
His confirmation came a day after officials said the drone targeted a compound, and Khurasani said those killed in the strike were seminary students.
The spokesperson for the Health Ministry, Wahid Majro, said several of the wounded were in critical condition and he feared the death toll could rise further.
Kazim Ali, who was at the gathering, told AFP the force of the explosion shattered the windows of the mosque.
President Mohammad Ashraf Ghani called the attack a crime against humanity.
Brown hurt, but C's capture win
Brown, 21, is averaging 14.1 points per game in his sophomore season after being the third overall pick in the 2016 NBA Draft. As of now, the Raptors will have a chance to play against the Boston Celtics three more times before the playoffs begin.
On February 28, Ghani offered to allow the Taliban to establish itself as a political party and said he would work to remove sanctions on the militant group, among other incentives, if it joined the government in peace negotiations.
A soldier stands guard near the site of a suicide attack in Kabul.
On Thursday night, Taliban fighters attacked a joint army and police outpost in the northern province of Takhar, killing seven soldiers and 10 policemen, according to Khalil Aseer, a provincial police spokesman.
Alice Wells, a USA principal deputy assistant secretary of state in charge of South and Central Asian affairs, said Afghan President Ashraf Ghani's offer of talks with the Taliban without any preconditions was the "most specific and forward-leaning proposal" for peace since the US -led invasion in 2001.
In return, the militants would have to recognize the Kabul government and respect the rule of law. Now obviously the U.S. has a direct interest in the resolution of this conflict and the Taliban have frequently stated the need for all foreign troops to depart Afghanistan is a precondition for negotiations.