A suicide bomber has killed at least 27 people and wounded 35 in an explosion at a crowded Shi'ite mosque in the Afghan capital Kabul.
The attacker entered the Baqir ul Olum mosque during a ceremony on Monday, the interior ministry said in a statement.
Fraidoon Obaidi, chief of the Kabul police Criminal Investigation Department, said at least 27 people were killed and 35 wounded when the explosion tore through the worshippers.
There was no immediate claim of responsibility.
Although Afghanistan has not suffered sectarian violence comparable to that experienced by many Middle Eastern countries, the attack underlines the deadly new dimension that growing ethnic tension could give to its decades-long conflict.
In July more than 80 people were killed in an attack on a demonstration by the mainly Shia Hazara minority that was claimed by Islamic State militants.
Later Government Chief Executive Abdullah Abdullah condemned the attack as a sign of barbarism but said Afghanistan should not fall victim to "enemy plots that divide us by titles".
"This attack targeted innocent civilians - including children - in a holy place. It is a war crime & an act against Islam & humanity," he said in a message on Twitter.