PROVIDENCE — There was a severe outbreak of crime, especially violent crime, in the city in the first six months of 2008 compared with the same period in 2007, the FBI reported yesterday.

The number of violent crimes went up from 440 to 553, an increase of nearly 27 percent.

Muggings for cell phones — a phenomenon in large cities and some midsize cities across the nation — appear to be a major factor in the rise. The police have said that muggings are difficult to prevent because they are crimes of opportunity.

Of late, one-third of all robberies are for cell phones, Police Chief Dean M. Esserman said. Robberies skyrocketed by 60, from 170 to 230, or 35 percent, during the first six months.

The police have made inquiries with a cell phone research and development company, Qualcomm, and with the FBI to find a way to render stolen cell phones unusable to robbers and, therefore, unattractive to grab.

All told, there were 4,866 violent and property crimes reported through June 30, compared with 4,217 the year before, an increase of more than 15 percent. In addition to the cell phone muggings, break-ins at foreclosed and abandoned properties appeared to account for a significant portion of that increase.

Although the Police Department has not yet calculated final figures for the entire year, Esserman said the full-year figures will show that crime was up but by a less dramatic percentage than in the first six months. Some crime categories will show decreases, he said.

There were more murders in the first six months of 2008 compared to that period in 2007 –– eight, compared with five — and Esserman pointed out that by the end of the year, the situation had reversed itself. There were 13 murders in all of 2008 compared to 14 in 2007.

“Every day we’re putting our heads together, over what to do about it,” Esserman said of the spike in crime.

Violent crime includes murder, rape, robbery and aggravated assault. Property crimes are burglary, larceny, motor vehicle theft and arson. Put together, the categories compose what the FBI calls Part I crime, or the more serious segment of all crime.

The FBI statistics represent figures reported by states and localities, and due to the time required to collect and organize the data, they are the most recent figures available.

Nationally, the rate of violent crime for the same six-month period declined by 3.5 percent and for property crime, by 2.5 percent, according to the FBI. But that figure lumps rural townships in with major cities. Esserman said he does not have figures for cities comparable to Providence.

The police acknowledged at midyear that the rate of violent crime had shot up, and they expressed concern. Included was a greater frequency of shootings.

Esserman said then that the police would redouble their efforts to stem the trend, which had followed an apparent long-term decline in violence in Rhode Island’s capital city.

Among the steps taken were the repeated deployments of Neighborhood Response Teams, which pair state police troopers and Providence patrol officers. And the statewide High Intensity Drug Trafficking Area task force, which is administered by the FBI and the state police, temporarily put more officers in Providence at Esserman’s request.

The department spent more money on overtime to keep officers on the street, he added.

For the first six months of 2008 compared with the year-earlier period, property crimes went up from 3,777 to 4,313, an increase of more than 14 percent. Within that grouping, the incidence of burglaries and break-ins in Providence leaped from 684 to 904, a jump of about 32 percent.

Many of the break-ins, the police say, have been propelled by thieves’ quest for salvageable metals, such as copper. Criminals have been breaking into unoccupied and neglected houses and stripping them of copper piping, boilers, ductwork and other infrastructure.

In recent months the price of copper, along with the prices of other commodities, has plummeted worldwide. And that has given hope to law enforcement and real estate interests that the thievery problem may have crested.

“The theft of copper has gone down,” said Deputy Police Chief Paul J. Kennedy.

By happenstance, police supervisors were at the department’s annual retreat, at the downtown offices of the Rhode Island Foundation, when the FBI released the data. At the retreat, they brainstorm and discuss the issues that they confront.

gsmith@projo.com