A gunman killed a top federal police official and his bodyguard Thursday as they ate lunch in Mexico City, the latest attack against authorities waging a nationwide battle against organized crime.
Insp. Igor Labastida was among officers in charge of combatting contraband, said Public Safety Department spokesman Eduardo Cano.
Labastida's two other bodyguards and a woman who was a Public Safety administrative employee were injured, Cano said. Preliminary investigations indicated a lone gunman opened fire on Labastida and his companions before fleeing.
The assault was the latest against Mexican officials involved in the nationwide fight against drugs and organized crime.
The motive for the attack was unclear and police officials had made no arrests.
Follows police chief's slaying
But Cano said authorities were investigating a possible link to the assassination of Edgar Millan Gomez, Mexico's acting federal police chief. Millan Gomez was shot dead in May at his Mexico City apartment. Police blamed the Sinaloa drug cartel and arrested five people, including the alleged gunman.
"It's part of what's been happening," said Cano, referring to a series of attacks against federal officials.
President Felipe Calderon has sent more than 20,000 troops across Mexico to take back territory controlled by some of the world's most powerful drug gangs.
The cartels have responded with unprecedented violence, killing more than 4,000 people since Calderon took office in December 2006. More than 450 have been police, soldiers, prosecutors or investigators.
The homicides also have become more gruesome, with hit men beheading their enemies and leaving threatening messages with the victims' bodies.
Violence against police worst in north
Worst hit has been the north of the country, where police have been killed and others have resigned after their names appeared on hit lists.
At least two small towns have seen their entire police force disintegrate, with officers either killed or resigning for fear of being targeted.
The administration of U.S. President George W. Bush has cited the attacks on police in urging Congress to approve a plan that would give Mexico and other Latin American countries US$1.4 billion over several years to fight drug trafficking.
But U.S. lawmakers have sought to add conditions that have angered Mexican officials, including performance evaluations and guarantees that civilian investigators will be allowed to look into allegations of abuse by the Mexican military.