Taliban militants have banned the country's Helmand region from shaving or trimming men, saying the move violates Islamic law.
"Anyone who violates the law will be punished," the Taliban said.
Some barbers in Kabul have said that they too have received similar instructions.
The directive deals with the reinstatement of strict laws such as those that existed when the group was previously in power, despite promises that it would establish a moderate government.
Since taking power last month, the Taliban have severely punished its opponents.
On Saturday, militants of the group shot and killed four kidnappers and their bodies were dumped on a road in the province of Herat.
In a notice published in a salon, south of Helmand province, Taliban officials warned that barbers must follow Islamic law in shaving the scalp and beard.
No one was able to complain, said a notice seen by the BBC.
"The militants continue to come and order us not to shave our beards," said a barber in Kabul.
One of them told me that they could send officers to investigate and arrest us. "
Another barber, who runs one of the large salons, said he received a call from someone who said he was a government official.
They wanted him to stay out of American fashion and not to shave his beard. During the first Taliban leadership from 1996 to 2001, the group banned various hairstyles and insisted that men shave their beards.
But since then, shaving and short hair among Afghan men have become popular.
But some unnamed barbershop said that the new rules would make it harder for them to earn a living.
"For many years my salon was attracting young people who wanted to get their hair cut to look like modern teenagers," one told the BBC. There is no need to continue this business'
