Mexico City police committed a mass violation of civil rights when officers arrested 226 people earlier this week in the wake of the country's first big bout of flash-mob violence, the city's human rights commission says.

The circumstances suggest police targeted people, mostly youths, based on their appearance as constables swooped through streetside food stalls, the Plaza Reforma shopping mall, cafés and other venues, rights commission chairman Luis Gonzalez Placencia said.

"It's worrying because we're seeing the criminalization of an entire category of youth, singled out and profiled because of their appearance," Gonzalez Placencia says in Wednesday's edition of Mexico's El Universal newspaper. "We found that this was the only factor in common that could explain the detention of so many youths."

Gonzalez Placencia said his agency has affirmations from more than 70 young people who were arrested but say they had nothing to do with the flash mob. The police even hauled in a franelero, one of the capital city's street entrepreneurs who watch over parked cars for a fee, he said.

Ninety-one people were immediately released for lack of evidence, and only eight of those arrested — two adults and six minors — are still in custody, charged with participating in an assault on a subway rider who was robbed of a hat and watch, El Universal reported.

Packed reggaeton concert

The arrests, which the human rights commission characterized as a "raid," occurred Sunday after two young men called on other people to gather for a concert of reggaeton music at a club called Sixtynine, but hundreds more people showed up than could fit into the venue.

Mexico City police chief Manuel Mondragon said as many as 600 angry youths who couldn't get in to the concert went on a rampage at local subway stations, damaging turnstiles and streetlamps, robbing people and tossing fireworks in an area popular among foreign residents and tourists. A police car had its windshield smashed, he said.

Surveillance footage of the incidents shows hundreds of young people in subway stations and in the streets, occasionally chanting and jumping as they walk en masse through subway cars and staircases or march down boulevards.

In one scene, some of the young people knock down part of the wallboard in a subway station. In another, a group of five young men climb a wall in the same station to tinker with equipment on the ceiling. Still more footage shows youths pushing equipment down the stairs of a station.

Dozens of riot police swarmed into the Plaza Reforma mall to arrest some of the youths, causing some stores to temporarily lock their doors.

The use of social networks is growing in Mexico, but the country had largely escaped the kind of rapidly formed, fast-moving youth mobs seen in Europe and the United States before the outbreak of violence in the capital Sunday.