Afghanistan's Taliban has instructed all government employees to wear a beard and adhere to a dress code or risk being fired, three sources told Reuters, the latest of several new restrictions imposed by the hardline Islamist administration.

The sources said representatives from the Ministry for the Propagation of Virtue and Prevention of Vice were patrolling the entrances to government offices on Monday to check that employees were in compliance with the new rules.

Employees were being instructed not to shave their beards and to wear local clothing consisting of a long, loose top and trousers, and a hat or turban. They were also told to ensure they prayed at the correct times, two of the sources said.

Workers were told they would from now on be unable to enter offices and would eventually be fired if they did not meet the dress codes, the sources said.

A spokesman for the public morality ministry did not respond to a request for comment.

Last week, the Taliban banned women from taking flights without a male chaperone and failed to open girls' schools as promised.

On Sunday it ordered parks to be segregated by sex, with women allowed to enter three days a week, and men the other four days, including the weekend, meaning even married couples and families cannot visit together.

The Taliban administration has drawn criticism at home and from Western governments for forcing its hardline interpretation of Islamic law onto all Afghans.

The Taliban say they will respect everyone's rights in line with Islamic law and Afghan customs and that they have changed since their 1996-2001 rule, when they barred women from leaving the house without a male relative and forced men to grow beards.

Wednesday's u-turn on girls' schools led to protests from the international community, including the United States, which pulled out of planned meetings with Taliban officials in Qatar to discuss key economic issues.

The Taliban needs Western countries to lift sanctions that are crippling the Afghan economy.