Mexico City: A letter purportedly signed by a major Mexican drug cartel offers to dissolve the gang if the government promises to protect citizens in the western state where it is based, authorities said yesterday.

Prosecutors said they couldn't immediately verify the letter's authenticity — or the offer's sincerity — but stressed the federal government does not negotiate with drug cartels.

The one-page letter allegedly signed by "La Familia Michoacana" drug cartel was dropped in the streets of some mountain towns in the western state of Michoacan on Tuesday, according to the Michoacan bureau of the federal Attorney General's Office. It also showed up as a banner above an overpass and was sent as an e-mail to reporters.

Public commitment

The missive claims La Familia wants to protect Michoacan and its residents and says the group will disband if federal police promise to act honestly and fight to the death to defend the state.

"We have decided to retreat and return to our daily productive activities if the federal and local authorities ... promise to take control of the state with force and decision," read the letter, dated November 2010. "If the government accepts this public commitment and lives up to it, La Familia Michoacana will dissolve."

Federal officials, however, say the cartel itself has victimised Michoacan with kidnappings, extortion, hundreds of murders, decapitations and drug trafficking. Last year, they say, the gang unleashed a spasm of violence in which at least 18 police officers were killed. Last week, in response to the arrest of two members, the gang set ablaze trucks to block entries to the state capital and sprayed a shopping mall with automatic-weapons fire, the state attorney general's office said.

The letter allegedly written by La Familia says the gang's decision to possibly dissolve was motivated by alleged abuses against civilians by authorities conducting warrantless searches and arrests to combat the cartel.