The appearance of Saudi Arabia's first female Olympic athletes at the Games' opening ceremony has prompted a heated reaction, with some conservative Islamists denouncing them as shameless, but many praising them.
The debate raged as it emerged that one of the women, Wojdan Ali Seraj Abdulrahim Shaherkani, has said she would refuse to compete in the +78-kilogram judo category if she was banned from wearing a hijab.
Saudi newspapers reported that she had telephoned her father to say she would withdraw from the Olympics if she was forced to compete uncovered.
The president of the International Judo Federation, Marius Vizer, said last week that Shaherkani would have to fight without a hijab to comply with "the principle and spirit of judo".
Along with 800-metre runner Sarah Attar, Shaherkani marched behind the men of their national delegation during the Olympic opening ceremony.
Conservative Muslim clerics in Saudi Arabia oppose women's sport, arguing that it is immodest and against their nature.
That view was reflected in Twitter postings, including one under a hashtag that would translate as "Olympic_Whores".
"One should not hesitate to describe their participation as shameful and a great sin," Khaled Al Jabri, whose Twitter profile listed him as a Saudi from Jeddah, wrote in one of thousands of postings on the subjecty.
"Whores of the Olympics ... They want to run so that they intentionally fall down and reveal [their figures]," said a tweeter using the name mloven2100, another Saudi.
But supporters of the athletes hijacked the hashtag to post messages in their defence.
"I'm proud of Saudi women's participation in the Olympics," wrote Fahad Al Enzi, a member of a prominent Saudi tribe whose profile listed him as from Riyadh.
A woman who identified herself as Safaa, a Saudi, tweeted: "Women walking behind the Saudi delegation is historic. Next we'll be carrying the flag and walking side by side, equal."
Before this year, Saudi Arabia was one of three countries, alongside Brunei and Qatar, never to have sent female athletes to the Olympics. The latter two confirmed earlier this year that their delegations would include women.
Saudi Arabia agreed a deal on the participation of Shaherkani and Attar just two weeks ago in talks with the International Olympic Committee (IOC). Human-rights groups had urged the IOC to ban the country from the Games unless it agreed to send women.