At least 120 people - 100 of them police officers - have been injured in clashes during anti-government protests in Mexico City, police said.
Thousands of demonstrators marched in the Mexican capital on Saturday to protest against violent crime and President Claudia Sheinbaum's government.
Sheinbaum said the marches, which also took place in other cities, had been funded by right-wing politicians who oppose her government.
The rally was organised by Gen Z youth groups, drawing support from citizens protesting against high-profile killings, including the assassination just weeks ago of Uruapan Mayor Carlos Manzo - who had called for tough action against cartels.
Demonstrators dismantled parts of a barrier protecting the National Palace, where Sheinbaum lives, as police protecting the compound used tear gas on the crowds. Authorities have arrested 20 people for crimes including robbery and assault, Mexico City security chief Pablo Vazquez told reporters.
Protesters waved banners displaying messages like We are all Carlos Manzo, with some wearing cowboy hats to pay tribute to the late mayor.
Manzo was shot on 1 November while attending a Day of the Dead festival, known for his vocal stance on drug-trafficking gangs and cartel violence. He had demanded tough action against armed cartel members.
Despite mixed reviews regarding her handling of cartel violence, Sheinbaum has endeavored to retain approval ratings above 70% in her first year while making significant efforts against fentanyl trafficking, a pressing concern for the U.S.
The protests come amid criticism that Sheinbaum has not effectively addressed the violence plaguing Mexico, along with strained international relations, including being declared persona non grata by Peru earlier this month.