The city's two-year effort to consolidate the fight against street gangs is poorly monitored and nobody knows whether it's responsible for a drop in gang violence, according to an audit released Tuesday.

Still, progress has been made in following a 2008 blueprint for coordinating efforts to fight gangs and prevent at-risk kids from joining them, City Controller Wendy Greuel said in releasing the audit.

Gang Reduction and Youth Development, which is run out of the mayor's office, has laid a solid foundation for a comprehensive anti-gang strategy but it needs better oversight, Greuel said.

"This calls into question the effectiveness of the city's approach to keeping our communities safe and gang-free," said a statement from the controller's office.

In the past two years, gang-related crime in areas where the program is operating has dropped 10.7 percent, according to Guillermo Cespedes, the mayor's appointed gang czar.

But gang crime also is down in other areas and Greuel said it was unclear whether the program was working because the Urban Institute, which received $525,000 to evaluate the program, still has not released results after a year.

"It is impossible to measure the overall success" of the efforts, the statement said.

The evaluation is now expected to take another 18 to 24 months, according to the controller's office.

Mayor Antonio Villaraigosa said the findings show progress and that "we've radically changed the way City Hall fights gang violence."

"Now is the time to take that next step in evaluating exactly what programs and what services are causing the drop in gang violence," the mayor said in a statement.