Egyptian authorities arrested seven people they accuse of promoting homosexuality by raising a rainbow flag in support of LGBT rights at a concert last week.

The seven were arrested in the conservative, mostly Muslim country on charges of “promoting sexual deviancy,” a euphemism for homosexuality in Egypt, Reuters reported.

The group was reportedly seen on camera raising the rainbow flag at a Mashrou’ Leila concert, a popular Lebanese alternative rock band whose lead singer is openly gay.

Although homosexuality is taboo in Egypt, it is not explicitly against the law. In practice, however, the government regularly seeks to prosecute people under charges such as “immorality” or “debauchery.”

Not long after the concert, some of the images and videos of the flag-raising went viral, with some people praising the move and others condemning it.

The public prosecutor has not yet announced a decision on whether formal charges will be filed and a case brought to court, Reuters reported.

“We are against gay art,” said Reza Ragab, the deputy head of the official musicians union, in a phone interview on AlAssema TV.

Egyptian writer Mona Eltahawy condemned the actions of the authorities and the musicians syndicate on Twitter.

Mashrou’ Leila has played in Egypt before, but the group was twice banned from performing in Jordan over allegations its musicians violate the kingdom’s traditions and commit blasphemy. It is one of the Arab world’s few rock acts to achieve resonance in the West, playing its Arabic-language fusion to a growing number of fans in Europe and the United States.

The biggest crackdown on gay people in Egypt came in May 2001 when 52 men were arrested aboard a floating nightclub called the Queen Boat, charged with “habitual debauchery” and “obscene behavior.” Their first trial prompted outrage from human rights organizations, the United Nations and the U.S. However, 21 of the men were eventually sentenced to three years in prison after a retrial.