Mexico has been shaken by yet another weekend of drug prohibition violence, with 34 deaths blamed on drug trafficking organizations and a series of grenade attacks that injured a dozen people.

Raul Benitez, a security expert at the National Autonomous University of Mexico, says that the spate of recent deaths may be no coincidence: It comes as the federal government is increasing intelligence capabilities and taking a harder look at collusion between traffickers and local police and authorities, as it looks to centralize the police force. Therefore, many mayors who once may have turned a blind eye to trafficking exploits in their towns might now be refusing to cooperate. “If the mayor is an obstacle, that is when the problem starts,” says Mr. Benitez.

Authorities say gunmen have killed the mayor of a northern Mexican town — adding to a string of attacks on political figures in the drug prohibition-plagued region. Mayor Prisciliano Rodriguez Salinas was gunned down yesterday along with another employee of the town named Doctor Gonzalez, about 50 kilometers east of Monterrey. Rival gangs have been battling to control drug routes through Nuevo Leon and neighboring border states.

The death toll from an ambush staged against police in the southern Mexican state of Guerrero has risen to eight, with one officer wounded, officials said.