French government ministers have tweeted their support for the teenager after some social media users called for him to be decapitated.
Police in France are investigating after a teenager was targeted with online death threats after posting a "joke" tweet about the Hajj.
The Twitter user, known as "Hugo", uploaded a photo on Saturday of the pilgrimage to Mecca, Saudi Arabia, with a reference to the television game show InZeBoite.
InZeBoite is a family television programme on the Gulli channel, which features two competing teams and a ‘Black box’ maze.
The tweet sparked dozens of insults and threats from Internet users, who claimed it showed a lack of respect for Islam. Some said they wanted to physically attack the teenager at his home or at school.
Following the death threats, Hugo tweeted on Sunday morning saying he had never intended to offend anyone.
"I did not know that it was going to grow so much. Sorry again. Leave me alive [sic]."
Both tweets have since been deleted.
Many people reached out to Hugo with messages of support, using the hashtag #JeSoutienHugo.
The Secretary of State for Equality, Marlène Schiappa, posted on Twitter that France has no law against blasphemy, but that widespread cyberbullying should be punished.
"France is a secular republic, where everyone can criticize and mock religions without being threatened with death."
The new Minister of State for the Digital Sector, Cédric O, also tweeted that cyberbullying of this sort was "reprehensible".
Several users also reported the death threats to France’s online policing platform, Pharos, and Police Nationale confirmed to Euronews that an investigation was ongoing.
In France, online stalking can carry a prison sentence of up to two years and fines of €30,000, with greater penalties when the victim of cyberbullying is under 15 years old.