Mayors from the northern border states of Tamaulipas, Chihuahua and Nuevo Leon have moved to the US, with some taking up residence in that country permanently and others splitting their time between US and Mexican residences, municipal officials told EFE.
The mayors of at least six border cities in the northeastern state of Tamaulipas have moved to neighbouring US state of Texas.
"The advantage for them is that they cross the Rio Bravo (Rio Grande) river and they are in their city hall or their home," an official of the ruling National Action Party (PAN) said.
Five mayors have been murdered in the past six weeks, with a total of 10 killed this year.
About 15 mayors have been killed since President Felipe Calderon declared war on Mexico's drug cartels shortly after taking office in December 2006.Crime has surged in some cities in Nuevo Leon and people are moving to other parts of Mexico and the US, a state legislator said.
Drug cartels threaten officials to keep them from interfering with their criminal activities.
Many of the cities have only between two and five patrol cars for the average of 30 police officers on the payroll, and officers have few firearms to take on criminals, officials said. Some high-level officials and their families have also been forced to flee to the US.