Some women have been straying from the black, all-covering chador

Clothing shops and factories have been given a written order to stop producing clothes that stray from the strict female dress codes, the head of a clothing trade union in Tehran told a local newspaper.

Long, shapeless black coats and head coverings have been mandatory women's wear - regardless of religion - since the country's Islamic revolution 24 years ago.

However, in recent times some Iranian women have been sporting shorter, paler coats that end at the knee and hug the body.

Some don colourful headscarves that allow their hair to spill out from underneath.

But now dress shops have been told they have a month to clear their shelves of items that do not conform to the code.

Some traders in various shopping districts in Tehran told news agency AFP they had already been raided by police.

Tug of war

Street patrols by the morals police have also been noticeably stepped up, and shops and restaurants have been told to bar women not deemed to be respecting the dress code.

Under more moderate Khatami some have bent the rules

Such crackdowns occur periodically in Iran, usually after protests from conservatives that women are beginning to skimp on their clothing.

Many women have felt emboldened to push the boundaries of conservative strictures since the 1997 election of reformist President Mohammad Khatami.