Nuevo Leon state security spokesman Jorge Domene Zambrano says the officers stood by while Police Chief German Perez in Santa Catarina was attacked.Getty Images
Murder in Mexico shot up 23 percent in 2010 over the previous year, according to Mexican statisticians.
The National Institute of Statistics and Geography recorded 24,374 homicides over the course of last year, a 23 percent increase from 19,803 in 2009. Last year's figure represented 22 killings for every 100,000 residents in the country.
Many but not all of the homicides were committed by organized crime organizations, the institute told The Associated Press.
Violence has risen in many Mexican regions as a result of drug trafficking and other organized criminal activity. President Felipe Calderon's office has said that more than 15,000 homicides in 2010 were attributed to organized crime.
According to the statistics institute, the U.S.-bordering state of Chihuahua saw the highest number of homicides with 4,747. Sinaloa, in northwestern Mexico, registered 2,505.
Sinaloa is the headquarters of the Sinaoloa cartel, while Chihuahua includes the violent border city of Ciudad Juarez. Those two states are among the most affected by drug violence, and together they accounted for 29 percent of Mexico's homicides.
The institute cautioned that its information was preliminary and said it awaited definitive results that are to be released in September.
In the northern state of Zacatecas, prosecutors said a town mayor was found shot to death lying alongside a slain local farm union official Thursday, a day after they were kidnapped by gunmen.
The dead mayor, Fortino Cortes Sandoval, headed the city government in Florencia de Benito Juarez. Last week, soldiers killed six suspected cartel hitmen during a firefight on a highway linking Sandoval's city with the Teulada municipality.
A dozen mayors have been killed in Mexico since last year, many of them victims of violence related to drug cartels.
Two metric tons of marijuana were seized by authorities in Puerto Penasco, Sonora, about 60 miles (100 kilometers) from the U.S. border at Arizona, along with weapons and a vehicle, the Defense Department reported. No further details were available.
And military officials reported the seizure of 22 tons of ethyl phenylacetate in the port of Manzanillo in Colima state that had been shipped from Shekou, China. The chemical is used in the production of methamphetamine.
This is based on a story by The Associated Press.