More than 40 people were wounded in the attack at the front of the mosque in Maymana, capital of Faryab province.
 
The provincial governor and police chief were said to be among those attending the prayers to mark the Eid al-Adha holidays, but they reportedly escaped without serious injury.
 
Civilians and police officers were among the dead, officials said.
Eye witnesses and officials said the suicide attacker approached the mosque and detonated his suicide vest after the Eid prayers had finished.
The BBC's Bilal Sarwary in Kabul says it is not clear now the attacker managed to get past at least four security checkpoints to target the mosque.
 
Deputy provincial governor Abdul Satar Barez told the AFP news agency that the attacker himself was wearing a police uniform.
 
Attacks in northern Afghanistan are far less common than in the south and east, and Faryab province has been considered to be relatively peaceful.
 
However at least 10 people were killed in an incident in April 2012 when a suicide bomber on a motorbike targeted a meeting of officials near the main vegetable market in Maymana.




Other News:
Afghanistan mosque suicide bomb attack kills at least 37
Shootings, explosions take at least 12 lives in Iraq
Germany opened a long-awaited memorial to Nazis' Gypsy victims
LONDON (Reuters):Buzzard oilfield yet to restart;
Argentine ship's crew arrives home from Africa
Somali reporter killed, raising toll to 16
Huawei partner offered US tech to Iran
Greeted like a rock star, Romney looks to transform momentum into votes