Some images posted on social media showed a number of bloodied corpses lying amid a scene of devastation outside the mosque compound in the western Afghan city, the BBC reported.
Mujib Rahman Ansari, the cleric of the mosque, was killed in the blast.
“Unfortunately, the country’s popular religious scholar Mawlawi Mujib Rahman Ansari has been martyred in a cowardly attack during the Friday prayers in Herat,” a Taliban spokesman tweeted.
It is not yet clear who is behind the attack, which the Taliban denounced as “sinister” and “cowardly”, the BBC reported.
The killing is the latest in a string of assassinations of prominent pro-Taliban figures in the country.
According to police, Ansari was arriving at Gazargah mosque to lead Friday noon prayers when a suicide bomber kissed the cleric’s hand and detonated an explosive device.
The cleric was well-known in Afghanistan for his support of the Taliban’s rule.
Speaking earlier this summer at a religious gathering in Kabul, he called for those who committed “the smallest act against our Islamic government” to be beheaded.
