(CNN) -- The mayor of crime-ridden Camden, New Jersey, has announced layoffs of nearly half of the city's police force and close to a third of its fire department.

One hundred sixty-eight police officers and 67 firefighters were laid off Tuesday, as officials struggle to close a $26.5 million budget gap through a series of belt-tightening measures, Mayor Dana Redd told reporters. The layoffs take effect immediately.

Redd said she was unable to secure the $8 million in budget concessions that she says she needed to save the jobs of up to 100 police officers and many of the city's firefighters.

The mayor -- who said she will continue negotiations with police and fire unions -- had been asking the workers to pay more for their health care, freeze or reduce their salaries and take furlough days.

The apparent impasse has left administrators of a city with the second-highest crime rate in the nation scrambling to figure out solutions to keep residents safe. Camden is second only to St. Louis, Missouri, in annual rankings of cities based on compilations of FBI crime statistics.

Some clerical officers were demoted and reassigned to the streets, the mayor said, pledging that the cuts would not affect public safety.

"We're still going to protect our residents," said Robert Corrales, spokesman for Redd. Public safety "will remain our top concern. We'll shift our resources to be more efficient with what we have."

But police and firefighter union officials say the layoffs will most certainly have an impact.

"It's absolutely, physically impossible to cover the same amount of ground in the same amount of time with less people," said John Williamson, president of the Fraternal Order of Police union in Camden. "Response times will be slower."

One local business owner, David Brown, said he does not "understand how you can do more with less."

"I don't want to be a pessimist, but I can't be optimistic."

Camden resident and sanitation worker Gloria Valentin said she is now fearful that the city does not have enough police protection to keep people safe.

"Today is a real sad day in the city of Camden," she said.