Thousands of people filled the streets of cities across Mexico on Saturday to protest against government security policies, which they say have not been able to control the growing violence in the country.

The demonstrations, held under the banner of "Generation Z" and inspired by youth movements around the world, were driven especially by the killing of an anti-crime mayor earlier this month.

"Carlos did not die, the government killed him," shouted protesters in Mexico City as they remembered the mayor of Uruapan in the western state of Michoacan, who was shot dead during a public Day of the Dead event on November 1.

A small group of hooded protesters also pulled down metal barricades around the National Palace, where Mexican President Claudia Sheinbaum lives and works, which led to clashes with riot police who used tear gas and fire extinguishers in response.

"For many hours, this mobilisation proceeded and developed peacefully, until a group of hooded individuals began to commit acts of violence," Pablo Vazquez, Mexico City's security chief, told reporters.

"This is how you should have protected Carlos Manzo," some protesters shouted at the police, according to the Reuters news agency.

Mexico City's public safety secretary, Pablo Vazquez, said at a press conference that 100 police officers were injured, including 40 who needed to be treated at hospitals.

He added that 20 civilians were also injured, 20 people were arrested, and another 20 were "referred for administrative offences."

Earlier this week, President Sheinbaum questioned what was driving the protests and said at her usual morning press conference that the demonstrations were "inorganic" and "paid for."

"It is a movement promoted from abroad against the government," the Mexican president said, claiming that right-leaning political opponents played a major role and that bots on social media helped to spread the movement.

Although the protests included international symbols such as the pirate flag from the Japanese manga "One Piece," which has become a sign of youth protest across the world, many other elements were clearly rooted in Mexico.

Alongside banners remembering the late Uruapan Mayor Manzo, others demanded the removal of Sheinbaum's MORENA party.