On Friday, Saudi Arabian authorities began carrying out a sentence of 1,000 lashes for a citizen who criticized the country's powerful clerics on his liberal blog.

According to the London-based human rights organization Amnesty International, Raif Badawi was convicted of "insulting Islam" and is serving a 10-year prison term, during the course of which he is to receive 50 lashes once a week for 20 weeks, The Associated Press reports. He was also ordered to pay a fine of 1 million riyals, or about $266,600.

After Friday prayers, Badawi was brought to a public square in the port city of Jiddah and flogged 50 times before hundreds of spectators, a witness said. The blogger's feet and hands were shackled, but his face was visible; he did not cry out during the lashing, which lasted about 15 minutes.

In his "Free Saudi Liberals" blog, Badawi had criticized Saudi Arabia's influential clerics who follow a strict and ultraconservative interpretation of Islam known as Wahhabism, which in turn legitimizes the kingdom's ruling family. The website has been shut down, and activists say local authorities are using the case as a warning to other dissidents.

The United States had urged Saudi Arabia to cancel Badawi's sentence, which State Department spokeswoman Jen Psaki called an "inhumane" response to a citizen's exercise of free speech, Al Jazeera reports.

"The United States government calls on Saudi authorities to cancel this brutal punishment and to review Badawi's case and sentence," Psaki said.

Human rights organizations similarly expressed outrage over the sentence, which an appellate judge had further stiffened from the seven years in prison and 600 lashes originally imposed.

"It is horrifying to think that such a vicious and cruel punishment should be imposed on someone who is guilty of nothing more than daring to create a public forum for discussion and peacefully exercising the right to freedom of expression," said Philip Luther, Amnesty International's Middle East and North Africa director.

Badawi's wife and children, meanwhile, have left Saudi Arabia and resettled in Canada.