Two Saudi women were sent to anti-terrorism court this week for allegedly violating the country's ban against female drivers.

Loujain al-Hathloul and Maysa al-Amoudi were arrested weeks ago for opinions posted on social media, four sources told the Associated Press under condition of anonymity.

Authorities have not commented on the violations or the evidence against the women.

Research and advocacy organisation Human Rights Watch recently warned that "Saudi authorities are ramping up their crackdown on people who peacefully criticise the government on the Internet," and that judges and prosecutors are citing "vague provisions of a 2007 anti-cybercrime law to charge and try Saudi citizens for peaceful tweets and social media comments."

The Specialised Criminal Court to which the women were referred processes terrorism cases, as well as persons accused of activism, dissidence, and criticism against the government. Earlier this year, the court sentenced Shiite cleric Sheikh Nimr al-Nimr to death for sedition, and human rights lawyer Waleed Abul-Khair to 15 years for inciting public opinion.

Religious decrees have been issued by Saudi clerics forbidding female drivers, and women cannot get drivers licenses. Saudia Arabia is the only country in the world with such a prohibition. Al-Hathloul and al-Amoudi have a combined 355,000 followers on Twitter, and were outspoken supporters of a local campaign to end the driving restriction.

Al-Hathloul, 25, was arrested on November 30 while attempting to cross the border from the United Arab Emirates to Saudi Arabia carrying a UAE driver's license. Al-Amoudi, 33, was allegedly detained when she went to the border to deliver food and a blanket to al-Hathloul.

Sources said the women's lawyers appealed the transfer of the cases to the anti-terrorism court, and a decision on the appeals is expected in the coming days.