By Heba Saleh BBC News, Cairo

Islamic headscarves are banned in schools and government offices

The Tunisian authorities have launched a campaign against the Islamic veil worn by some women to cover their hair.

Police are applying with renewed vigour a decree dating back to 1981 which prohibits women from wearing Islamic headscarves in public places.

In recent days, senior officials have hit out at what they describe as sectarian dress worn by people who use religion to hide political aims.

Human rights groups describe the move as unconstitutional.

Police in Tunisia have been stopping women on the streets and asking them to remove their headscarves and sign pledges that they will not go back to wearing them.

Under a ban introduced in 1981, women in Tunisia are not allowed to wear Islamic dress in schools or government offices. Those who insist on it face losing their jobs.

One woman said she was barred from entering her son's school wearing a headscarf.

'Unconstitutional'

The President, Zine El Abidine Ali, described the headscarf as a sectarian form of dress which had come into Tunisia uninvited.

Other officials said Islamic dress was being promoted by extremists who exploited religion for their political ambitions.

Tunisian human rights activists accused the authorities of depriving women of a basic freedom guaranteed by the constitution.

They say many people are upset by the ban, but that in a country where dissent is not tolerated they dare not show their anger.

Mr Ben Ali has been keen to restrict the spread of ideas or signs and religious symbols which could strengthen the country's outlawed Islamic opposition.

In the 1990s he moved to crush Tunisia's main moderate Islamic movement when fighting erupted in neighbouring Algeria between Islamists and the state.