The doctor, who preferred to remain unnamed for security reasons, is at the Mirwais hospital where victims from the blast are being treated.
The spokesman for the Taliban-run Ministry of Interior, Qari Saeed Khosty, also confirmed the explosion on Twitter and said that a number of people were killed and other injured.
Last week, at least 20 people were killed and 90 others wounded in a blast from a suicide bomber at another Shia mosque in the northern Afghan city of Kunduz on Friday.
This is a breaking news story, more to follow.