The blast occurred at Friday prayers, when mosques around the country are packed with worshippers. "The attacker was stopped at the gate and detonated himself," a security source told AFP

IS said one of its militants had targeted the congregation, detonating an explosive vest and "inflicting a large number of deaths and injuries", according to the SITE Intelligence Group, which monitors jihadist communications

Pakistan Prime Minister Shehbaz Sharif vowed that those behind the blast would be found and brought to justice

The attack was the deadliest in the Pakistani capital since September 2008, when 60 people were killed in a suicide truck bomb blast that destroyed part of the five-star Marriott hotel

UN Secretary-General Antonio Guterres said "attacks against civilians and places of worship are unacceptable", according to his spokesman