A Saudi human rights lawyer says an activist has been sentenced to 10 years in prison and banned from travel abroad for another decade.

Abdel-Karim al-Khadar, a professor of Islamic Studies from the conservative province of Qassim, has been under arrest since April 2013. He was considered among the most vocal critics of religious extremism and militancy. He had posted videos online giving religious lectures in support of greater women's rights and co-existence.

The rights lawyer, who spoke anonymously for fear of reprisal, told The Associated Press Tuesday that al-Khadar was sentenced Monday by Saudi Arabia's Specialized Criminal Court.

He is the third rights activist to be sentenced to prison in the past week, and was a founding member of the Saudi Association for Civil and Political Rights.