The incident took place on Sunday evening after an explosive device was detonated close to Imam Mohammad Baqer mosque.
Provincial governor’s spokesman Jilani Farhad confirmed the incident and said the explosion took place close to the Shi’ite mosque, leaving at least 6 wounded, including a woman.
Farhad further added that the health condition of one of those injured in the explosion is critical and is being treated in the hospital.
No group including the Taliban insurgents has so far claimed responsibility behind the incident.
Herat is among the relatively calm provinces in West of Afghanistan but the anti-government armed militants have recently increased to their insurgency activities.
Attacks target mosques are not rare in Afghanistan as the anti-government armed militant groups frequently use the sacred sites for terrorist attacks.
Numerous attacks target the Shi’ite Muslims have taken place in key cities of the country during the recent months, including capital Kabul.
The loyalist of the Islamic State of Iraq and Syria (ISIS) terrorist group normally claim responsibility for such attacks.