Federal law enforcement officials announced earlier this week a new “surge” strategy for fighting violent crimes in cities across the United States.

U.S. Attorney General Eric Holder unveiled the strategy Monday in Philadelphia, a city where murders and other violent crimes have spiked in recent years. During a news conference with Philadelphia Mayor Michael Hutter, Holder said the federal government had assigned more than 50 agents, intelligence analysts and investigators to the city for a four-month period.

The surge has been underway in Philadelphia since early June. Federal law enforcement officials completed a similar program in Oakland, Calif., earlier this year and have initiated another one in New Orleans.

Holder said the new strategy had so far been a success, and the federal government was examining ways to expand it to other cities.

“Especially in this time of economic and budgetary challenges — when police departments and other agencies at every level of government have been called upon to confront growing demands with increasingly limited resources — the need for cooperation and coordination among all relevant authorities has never been more clear,” he said.

The new strategy could provide relief for cash-strapped cities, understaffed police departments and backlogged courts. Federal law enforcement officials will likely focus on violent criminals who would be subject to federal prosecution.

“What they're hoping to do is to use the federal system, which doesn't let these guys just walk out on bail,” said Wall Street Journal reporter Evan Perez. “Under the state system, which is very overwhelmed in Philadelphia, it's very easy to get bail.”

Holder said the Philadelphia surge had led so far to more than 300 arrests and the seizure of more than 80 firearms, Perez reported.

But the program is not without its critics. Congressional Republicans say violent crimes are something cities should handle themselves, without federal interference. But while most cities have seen a reduction in violent crimes in recent years, the crime rates in cities including Philadelphia, Oakland and Chicago continue to rise.

“It's hard for the federal government to say no to cities like that, that need help,” Perez said.

On Tuesday, Holder was in New Orleans to announce a series of court-supervised reforms of the city’s police department that are some of the strictest ever imposed on a law-enforcement agency, the Washington Post reported.