MEXICO CITY (Reuters): Mexico arrested its head of Interpol on Tuesday for allegedly working for a powerful drug cartel and sent the military to take over police duties in the city of Tijuana in another step to flush out corrupt law enforcement.Ricardo Gutierrez was Mexico's representative to Interpol, the world's largest international police force, and the latest top police officer to be locked up on suspicion of working for drug traffickers.In October, two leading anti-drug agents were jailed for taking bribes of "up to $450,000 a month" from the Beltran Leyva crime group to leak intelligence about police operations.The Beltran Leyva brothers recently split from the Sinaloa drug cartel run by Mexico's most wanted man, Joaquin "Shorty" Guzman, and also were bribing Gutierrez, prosecutors said.