Herat Police spokesman Abdul Ahad Wali said the blast took place in Jebrayeel area of Herat city at around 5:30 PM (local time).
Wali noted the explosives were replaced in a three-wheel motorbike and were detonated in a crowded place near a Library.
According to Wali, all the killed and injured people are civilians.
He further added that Afghan security forces have discovered another motorcycle full of explosives in the area and thwarted it.
In the meantime, the spokesman of Herat hospital, Muhammad Rafiq Sherzay told Ariananews that all the killed and wounded civilians were transferred to the hospital and they are in critical situations.
Sherzay added that women are also among the killed and wounded people.