Egypt teenager detained following brutal mob sexual assault
Five other suspects were released.
On Friday night, a 19-year-old woman was sexually assaulted by a young man, who reportedly attempted to strip off her dress, after she left a friend's wedding.
Shortly after, dozens of other young men joined him, while others gathered to watch, according to local media.
Police had to fire shots in the air to disperse the crowd and save the woman, who was then taken to a local police station.
A video of the gathering crowds and the arrival of the police at the scene later emerged on social media.
Egypt has one of the world's highest rates of sexual harassment.
Awareness of the prevalence of mob sexual harassment against women began increasing in 2006 after bloggers posted videos of mass assaults that took place over Eid holidays.
In 2013, a UN report said that 99.3 percent of women in Egypt had been subjected to one form or another of sexual harassment.
In 2014, Egypt passed a law criminalising sexual harassment, with a fine of LE 3,000 to LE 5,000 ($166 to $277) and/or a jail sentence of no less than six months.
In January, a parliamentary committee approved a draft bill pushing for tougher penalties than those in the existing law.
However, the law is rarely enforced, with a lack of specialised police and an over-riding fear among survivors of the social stigma associated with sexual harassment.