Mexico's public security minister resigned on Friday less than two months after a quarter of a million Mexicans marched to protest lawlessness in one of the world's most crime-ridden countries. Alejandro Gertz left the government of President Vicente Fox, a presidential spokesman told Reuters, but no explanation for the resignation was given. Fox was scheduled to make a statement later on Friday. In the biggest demonstration in Mexico in more than 10 years, about 250,000 people dressed in white marched through the capital on June 27 to protest the failure of authorities to control soaring rates of kidnappings and other violent crime. Even crime-hardened Mexicans have been shocked by a recent wave of kidnappings. In one case in May, two brothers were abducted, shot dead and their bodies dumped in a garbage bin even though their parents paid a $600,000 ransom. A group of businessmen hired New York's crime busting former mayor Rudolph Giuliani last year for $4.3 million to tackle Mexico City's crime. City hall police say tough new "zero tolerance" measures in the capital are working. But kidnapping, murders and assaults are still widespread, especially in and around the capital. In mid-June federal police arrested a group of elite policemen in Mexico City who kidnapped businessmen using false arrest warrants. The June march was directed as much at Fox, of the conservative National Action Party, as at his leftist political rival Andres Manuel Lopez Obrador, the mayor of Mexico City and a leading presidential candidate in 2006.