(Recasts with arrest of second top police official) MEXICO CITY, Nov 20 (Reuters) - Mexican prosecutors have arrested two former aides in the government's brutal war against drug gangs, the latest sign that cartels have infiltrated the security forces' top brass. Mario Velarde, a head of the federal police force's anti-drug unit who formerly served as a top aide to Security Minister Genaro Garcia Luna, was detained on Wednesday, a government source who requested anonymity told Reuters. Mexico's attorney general's office said on Thursday it had also arrested the former head of the country's special office investigating organized crime, Noe Ramirez, who quit the post this year amid rising drug violence and kidnappings. Velarde and Ramirez are the latest in a string of high-profile officials to be locked up on suspicion of colluding with drug traffickers. Mexican media said Velarde was the fifth colleague of Garcia Luna's to be investigated by the attorney general's office and had been identified from a photo by a witness protected by the U.S. Drug Enforcement Administration, or DEA. "He has already been preventively detained as part of 'Operation Clean House,' which is uncovering public servants who leaked classified information and is focusing on the Beltran Leyva (drug gang)," the source said. The sweeping Mexican operation to flush out drug informants from the government and security forces this week caught Mexico's Interpol chief, Ricardo Gutierrez, who was alleged to be on the payroll of the Beltran Leyva cartel. Last month, two leading anti-drug agents were also jailed for taking bribes of up to $450,000 a month from the Beltran Leyva gang, and local media said there was evidence a cartel spy had infiltrated the U.S. Embassy in Mexico. The Beltran Leyva brothers were former hitmen for the Pacific-coast Sinaloa drug cartel run by Mexico's most wanted man, Joaquin "Shorty" Guzman, but recently split off in a violent feud. Widespread corruption among Mexico's badly paid police is undermining President Felipe Calderon's army-backed war on drug gangs, which has claimed more than 4,300 lives this year as rival cartels lash back at the army and each other. Some 500 local police in the northern border city of Tijuana were suspended this week in a bid to weed out corrupt officers and the army, which is broadly seen as cleaner, took over policing duties. (Reporting by Anahi Rama and Armando Tovar, editing by Philip Barbara)
A man holds up an image from a surveillance camera that shows a plane (R, top) during a news conference in Mexico City, November 14, 2008. Turbulence from a nearby aircraft, ...
