Oct. 3 (UPI) -- Egyptian authorities have arrested 33 people in a crackdown on homosexuality after rainbow flags were displayed last month at a pop concert, Amnesty International said Tuesday.
Those arrested -- all but one of them men -- have been detained since the Sept. 22 concert in Cairo, the activist organization said in a release.
The rainbow flag was displayed at a concert by Lebanese band Mashrou' Leila, whose lead singer is openly gay.
Three days later, Public Prosecutor Nabil Sadek ordered State Security prosecutors to investigate an "incident" because it "incited homosexuality."
"In a matter of days the Egyptian security forces have rounded up dozens of people and carried out five anal examinations signalling a sharp escalation in the authorities' efforts to persecute and intimidate members of the LGBTI community following the rainbow flag incident," Najia Bounaim, North Africa campaigns director at Amnesty International, said in a statement.
One day after the concert, a 19-year-old man was arrested on charges of "debauchery and sentenced last week to six years in prison, followed by six years of probation.
At least 10 people were arrested between Thursday and Saturday, and put on trial alongside another six arrested earlier in the week.
On Sunday, one man was detained in the Mediterranean port city of Damietta linked to the rainbow flag display. Six more people were also detained in Cairo in the last 48 hours for promoting "habitual debauchery" through online dating applications and four further arrests took place from a flat in Giza, also in the last 48 hours.
One woman has been charged with "promoting sexual deviancy" and "habitual debauchery."
"The scale of the latest arrests highlights how dangerously entrenched homophobia is within the country," Amnesty International said. "Instead of stepping up arrests and carrying out anal examinations, the authorities must urgently halt this ruthless crackdown and release all those arrested immediately and unconditionally."
Mashrou' Leila said in a statement Monday night that it had become apparent "that the state apparatus is hell-bent on executing the most atrocious of human rights violations. We cannot begin to explain how saddened we are to see yet another era of backwards tyranny creep over one of our most beloved countries and audiences."
The band has been banned from Egypt, according to the country's Syndicate of Musical Professions, over its "abnormal" art.
There are no specific laws against homosexuality in Egypt, but arrests are made on debauchery and immorality charges.
In 2001, police arrested 52 men in a raid on a floating disco called the Queen Boat.