Thousands protested across Mexico on Saturday under the banner of “Generation Z,” denouncing rising violence after the public killing of an anti-crime mayor earlier this month.

In Mexico City, a small group of hooded protesters tore down fences around the National Palace where President Claudia Sheinbaum lives, prompting a clash with riot police who deployed tear gas, according to Reuters witnesses.

Mexico City’s public safety secretary Pablo Vazquez said in a press conference that 100 police officers were injured, including 40 who required hospital treatment. Another 20 civilians were also injured, Vazquez told local media outlet Milenio.

The public safety secretary also said 20 people were arrested and another 20 “referred for administrative offenses.”

Other marches took place in various cities across Mexico, including in the western state of Michoacan, where anger has flared over the murder on November 1 of Uruapan Mayor Carlos Manzo, who was shot dead at a public Day of the Dead event.

Some demonstrators in Mexico City targeted their ire at Sheinbaum’s party, chanting, “Out, Morena.” Some also called for stronger state efforts to stop crime and violence, shouting, “Carlos did not die, the government killed him.”

A group calling itself “Generation Z Mexico” that called for the protests has said in a “manifesto” circulating on social media that it is non-partisan and represents Mexican youth that are fed up with violence, corruption and abuse of power.

Generation Z refers to people born between 1997 and 2012, on the heels of the millennials, and protest groups in other countries across the globe have taken on the label to push for social and political change.

Sheinbaum’s government has questioned the motives behind Saturday’s marches, saying they were organized in large part by right-leaning political opponents and promoted by bots on social media.