Thousands of white-clad people marched silently on Sunday to protest a surge of drug-related violence in a Mexican city across from Texas where the No 2 police officer was shot dead.
The crowd of several thousand students, church leaders, businessmen and politicians walked for about four miles (six kilometers) across Ciudad Juarez to a park near a border crossing, breaking the silence in a burst of speeches, dancing and singing.
More than 200 people have been killed so far this year in Ciudad Juarez. The city of 1.3 million across the border from El Paso, Texas, is 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 city and surrounding Chihuahua state in March.
Gunmen sprayed Roman Garcia's car with bullets outside his home _ months after his name appeared at the top of a hit list left at a monument for fallen police. Several people on the list have been killed, and none of the perpetrators have been caught.
"We need to unite against this," said Julian Ochoa, an architecture student at the march. "I hope we achieve something."
An increase in drug-related homicides, shootouts, kidnappings and car thefts near the border prompted US State Department to warn Americans last month of rising violence in the region, though it stopped short of advising against travel here.
A rash of attacks against police last week left at least four high-ranking officers dead. Mexico's acting federal police chief was gunned down Thursday in front of his Mexico City home.
President Felipe Calderon said the attacks show weakened gangs are trying to counter his fight against drug trafficking. Since taking office in 2006, Calderon has sent more than 25,000 soldiers to combat drug gangs across the country.
On Saturday, police arrested six suspected gang members after a gunfight in the northern state of Sinaloa. One of the six, Alfonso Gutierrez Loera, 25, identified himself as a cousin of suspected Sinaloa cartel chief Joaquin Guzman, according the Public Safety Department. Gutierrez Loera and another suspect were wounded in the shootout.