Saudi Arabia has introduced a system of SMS alerts to ensure married women in the kingdom cannot leave the country without their partners' consent.

Men who sign up to the service will receive an SMS alert on their mobile phone whenever any of their wives attempts to travel abroad. The husband will receive the alert even if he is travelling along with his spouse.

Saudi law already bans women from driving any vehicle, and requires them to wear a veil covering their entire body.

Women are required to get an authorisation letter signed by a male guardian if they intend to travel alone, according to the prevailing Islamic law.

Saudi author and journalist Badriya al-Bishr criticised the move saying "the authorities are using technology to monitor women", before condemning "the state of slavery under which women are held" inside the kingdom, according to AFP.

Bishir wrote in the Saudi Gazette: "To put an adult woman under the constant control of her husband is proof that the wife is a slave. If the husband is good, she will live in peace. If he is bad, she will face the destiny of a slave - she might be freed from slavery or live in torture."

The new system has also been castigated on social media. One twitter user compared women to cattle, while another wrote: "Hello Taliban, herewith some tips from the Saudi e-government!"

Another angry user quipped: "Why don't you cuff your women with tracking ankle bracelets too?"

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