The National Directorate of Security (NDS) in a statement said the militants were arrested during an operation conducted by the Special Forces of the Afghan Intelligence.
The statement further added that the group was led by commander Safiullah.
The other militants detained have been identified as Mushfiq, Wahidullah, Ghulam Mohammad, Baharuddin, and Syed Esa.
According to NDS, the group was actively involved in some major terrorist related activities in the vicinity of Enjil district.
The detained militants have confessed that they were involved in the murder of two police officers, one policeman, and several other terrorist activities.
Herat is among the relatively calm provinces in western Afghanistan but the anti-government armed militant groups are active in some of its remote districts and often carry out insurgency activities.
The province also witnessed deadly clashes among the rival Taliban groups last year and earlier this year which left scores of people dead.