Mexican Roman Catholic bishops on Tuesday urged drug traffickers to take advantage of Lent to give up crime and stop a wave of violence that has left thousands of people dead.

"We invite all of those involved in these absurd situations of drug trafficking to take advantage of Lent and start on a sincere path of conversion toward God," the bishops said in a letter distributed to the media.

The bishops called drug trafficking "a social sin" that results from "overvaluing material wealth." They also recognized government efforts to confront traffickers, and offered a prayer for victims of organized crime.

More than 2,500 people were killed in drug-related violence in 2007.

Lent, the period of penance between Ash Wednesday and Holy Saturday, is widely observed in this predominantly Roman Catholic nation.

Since taking office in December 2006, President Felipe Calderon has used the military to battle drug trafficking, sending more than 24,000 soldiers and federal agents into drug strongholds across the country. The violence has continued.

On Tuesday, authorities in the border city of Tijuana discovered the bodies of three men who had been strangled. The men, who have not been identified, were found on a street, with notes attached to their chests that threatened anyone who cooperates with soldiers or federal agents.

Also Tuesday, a deputy city police chief in the border state of Chihuahua was killed inside his home.