Washington, D.C. ? Violent crime has increased in some large cities in recent years in part because local police are too cash-strapped to fight it, the ATF chief said Monday.

The comments by Michael J. Sullivan, acting director of the Bureau of Alcohol, Tobacco, Firearms and Explosives, echo pleas by mayors across the country for more federal dollars to combat crime.

Sullivan described funding squeezes in many cities, like Chicago and Detroit, that “contribute to the potential of an uptick with regard to violent crime, because they don’t have as many resources to respond as quickly to it as they once did.”

Even so, he said, violent crime rates remain at what he called “record lows.”

Murders, rapes and robberies appear to be on the downswing after two straight years of violent crime increases, according to the most recent local police data reported to the FBI.

However, violent crime rose slightly in small cities and rural areas, while murder rates jumped by 5 percent in suburbs and 3.2 percent in mid-sized cities during the first half of 2007, the most recent data available.