Police fire rubber bullets and tear gas at striking farm labourers, who are pushing for pay rise to $13 a day.
More than two million intinerant workers, including many children, travel around Mexico picking fruit and vegetables, with much of the produce destined for the United States or Europe.
The labourers earn a fraction of what agricultural workers are paid in the US and often endure terrible conditions.
Last week more than 300 of the workers, including 78 children, were rescued from rat-infested living quarters in a farm in northern Mexico.
Al Jazeera’s John Holman reports