A grisly case of Mexico City police officers allegedly kidnapping and raping three teenage girls has shocked this crime-ridden city and turned up the spotlight on corruption in its police force.

Newspaper editorials Saturday said the alleged crime for which nine policemen were arrested Friday was a giant step backward in efforts to turn back a wave of violence in the Mexican capital and again stained the police's reputation."The illegal detention, kidnapping and rape of three young girls . . . are repugnant and intolerable acts that offend and embarrass the entire society and show, once again, the profound breakdown and lack of control that predominates in Federal District's Public Security Ministry," La Jornada newspaper said.

On Mexican radio talk shows, callers voiced their outrage at the crime, in a country where rapes are not commonly reported.

Authorities said three girls, ages 13, 15 and 18, stopped a police patrol car last Sunday in the eastern Mexico City district of Tlahuac to ask for directions.

The police offered them a ride to their destination but instead took them to the horse stalls of the Tlahuac district mounted police, Mexico City Deputy Police Chief David Almada told a news conference Friday.

The girls escaped Thursday.

Almada called the case "a monstrosity" and said 15 other policemen could be accused of covering up the incident.

President Ernesto Zedillo has acknowledged the country's police and judicial institutions are riddled with members who aided or committed crimes.

He has launched major anti-crime plans to stem kidnappings and thefts, mainly in Mexico City, that have targeted foreign businessmen and hurt investment in the country.

But critics say he and Mexico City's left-wing opposition party Mayor Cuauhtemoc Cardenas have failed in their efforts to reduce crime.