(CNN) -- The police chief of the violent Mexican border town of Nuevo Laredo has been missing for days, and state authorities are trying to find him, the Tamaulipas Attorney General's Office told CNN early Tuesday.

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Roberto Alejandro Balmori Garza was last seen over the weekend, spokesman Ruben Dario Rios said. Local media report that Balmori Garza's two brothers were found shot dead in the neighboring state of Nuevo Leon on Sunday. Local reports said one of his brothers was a federal prosecutor.

The Attorney General's Office would not confirm those reports to CNN. Widespread drug cartel-related violence has scared local officials into revealing little information about ongoing investigations.

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The state Attorney General's Office "has instructed a delegation in Nuevo Laredo to correspond to the respective authorities to establish the collection of information leading to determining the city official's whereabouts," a news release said.

In 2005, the police chief in Nuevo Laredo was gunned down on his first day on the job. In 2010, gunmen also killed a retired army general put in charge of police there.

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Nuevo Laredo has been the scene of violent attacks in Mexico's drug war.

Like most Mexican border cities, it offers rows of bars, inexpensive dentists, restaurants and cultural events to draw tourists. But tourism has sharply declined in the past six years as drug cartel violence has spiraled in Mexico. Because of the various bridges into the United States and access to a major highway, rival drug cartels are vying for control of Nuevo Laredo.

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Los Zetas, arguably the most violent Mexican drug cartel, are headquartered in Nuevo Laredo, which sits directly across the border from Laredo, Texas. The group has operations in at least 11 Mexican states and has been in a bloody turf war in northeast Mexico with the rival Gulf Cartel for the last several years.

In late 2011, the Texas Department of Public Safety warned against holiday travel to Nuevo Laredo, citing information that the Zetas may be targeting U.S. citizens.