Thousands of people wearing white marched silently in Ciudad Juarez to protest a surge of drug-related violence after the Mexican city's No. 2 police officer was shot to death.
The crowd of several thousand students, church leaders, business owners and politicians walked about four miles to a park near a border crossing, breaking the silence in a burst of speeches and singing.
More than 200 people have been killed this year in Ciudad Juarez, home base for the powerful Juarez drug cartel.
The assassination of police director Juan Antonio Roman Garcia on Saturday came despite the deployment of more than 2,500 soldiers and federal police to the area in March.