Khushnud Rakhmatullaev said the guards spotted the group of militants 250 km south of Dushanbe, the capital of Tajikistan, at around midnight. After a few warning shots in the air were made, the offenders "opened massive fire" supported by other militia located deeper on the Afghan side.
The shootout, which lasted for two hours, made the Afghan militia turn back.
He also said that some militants had been killed or injured since there were a lot of blood spots in the area.
An investigative team was sent to the area in the morning.
The war-torn Afghanistan is the world's largest heroin producer. The drugs are smuggled to other countries via neighbors, including Tajikistan.