As per the report from Tolonews and police spokesperson Mahmood Rasoli, the blast occurred at Gazargah Mosque just before Friday prayers, killing imam Mujib ur Rahman Ansari who was an influential pro-Taliban cleric known for his fiery speeches.
In July Ansari, in a speech at a religious gathering, had asked the government to behead anyone who commit the smallest act against the Islamic government.
The Taliban's spokesperson Zabiullah Mujahid, in a tweet expressed "strong condolences" over Ansari's death and said his attackers would be punished.
Ambulances transported 18 bodies and 21 wounded people from the blast to hospitals in Herat, said Mohammad Daud Mohammadi, an official at the Herat ambulance center,
Images on social media showed what appeared to be blood-stained bodies scattered around the compound of the mosque. The was no immediate claim of responsibility for Friday's blast.
Although the Taliban government says that they have improved security in the country since taking power around a year ago, but the frequency of blasts state otherwise. There have been several blasts in recent months, many targeting busy mosques during prayers.
On 18 August, the Afghan capital Kabul was shaken by a blast which ripped through a mosque packed with worshippers.
The United Nations has raised concerns about the growing number of attacks and some blasts have been claimed by a local branch of the Islamic State.
(With inputs from wire agencies)
This story has been published from a wire agency feed without modifications to the text.
