MEXICO CITY | The front-running candidate for governor in the violence-racked border state of Tamaulipas was assassinated Monday, the first killing of a Mexican gubernatorial candidate in recent memory.
Interior Secretary Fernando Gomez Mont suggested the killing of candidate Rodolfo Torre of the Institutional Revolutionary Party, or PRI, was the work of warring drug cartels whose battles have caused hundreds of deaths in recent months in the Gulf of Mexico coast state.
"These events reinforce the need to combat organized crime on all fronts," Mr. Gomez Mont said at a news conference. He refused to take questions.
Gunmen ambushed Mr. Torre's vehicle as he headed to a campaign event near the state capital, Ciudad Victoria. At least four other people traveling with him were killed.
"We firmly demand a rapid investigation of these events … and punishment for those responsible," PRI leader Beatriz Paredes said in a statement. "Nothing is going to intimidate us."
Attacks and threats against candidates in the run-up to Sunday's elections have raised fears that drug cartels may be trying to buy off politicians, and kill or intimidate those they oppose.
Mr. Gomez-Mont said the killings "fill all of society with indignation" and pledged to "find those responsible for these detestable acts, and bring them to justice."
The other main party in Tamaulipas — President Felipe Calderon's National Action Party, or PAN — said it would suspend the remaining three days of campaigning by its own gubernatorial candidate.
But PAN leader Cesar Nava said he hoped the elections could go forward Sunday. Twelve states are holding elections for governors, mayors and local posts.
Tamaulipas is one of the main trafficking corridors for drugs heading to the U.S. market, and in recent months it has been the scene of bloody shootouts between the Gulf cartel and its rival, the Zetas drug gang. The two former allies split several months ago, and have since been battling for turf.
Television footage from the scene of Monday's attack showed several vehicles and sheet-covered bodies along the side of the highway.
Mr. Torre is the highest-ranking election candidate killed in Mexico since presidential candidate Luis Donaldo Colosio, also from the PRI, was assassinated in 1994.