MEXICO CITY — Soldiers killed a top leader of the Sinaloa cartel in a raid on his posh hide-out, dealing the biggest blow yet to Mexico's most powerful drug gang since President Felipe Calderon launched a military offensive against organized crime in 2006.

Ignacio "Nacho" Coronel, a reputed founder of Mexico's methamphetamine trade, was gunned down trying to escape soldiers in the western city of Guadalajara. Mexican authorities said he fired on soldiers as helicopters hovered overhead and troops closed in.

Coronel was a close associate of Mexico's most wanted man, Sinaloa cartel leader Joaquin "El Chapo" Guzman, and was No. 3 in the organization after Ismael "El Mayo" Zambada.

"Nacho Coronel tried to escape, and fired on military personnel, killing one soldier and wounding another," Gen. Edgar Luis Villegas said.

The raid "significantly affects the operational capacity and drug distribution of the organization run by Guzman," he added.

Coronel's downfall came amid persistent allegations that Calderon's administration appeared to be favoring the Sinaloa cartel, or not hitting it as hard as other drug gangs.

Those allegations have drawn angry denials from the president and his top law enforcement officials, who point to the 2009 arrest of Vicente "El Vicentillo" Zambada — the son of Ismael Zambada — as proof they were going after the gang.

Coronel's death also was the biggest strike against Mexican cartels since drug lord Arturo Beltran Leyva and six bodyguards were killed in a Dec. 16 raid.