Burglaries in the Dupont Circle area have more than tripled this year. Thefts have spiked about 65 percent in neighborhoods east of the Anacostia River. In Columbia Heights, police are approaching people and warning them to put away their smartphones because thieves are snatching them.

Property crime is surging across the District in 2011. The most stubborn categories are burglaries, up 18 percent from this time last year (from 712 to 841), and thefts, which have increased 23 percent (from 1,469 to 1,803) through March 24, the latest date for which data are available.

“These two crimes have been the biggest problem we have for the past six months,” D.C. Police Chief Cathy L. Lanier said in an e-mail.

Violent crime in the District is down modestly in 2011. Gun crimes are on the decline, though homicides, at 20, are up from 18 at this time last year. Robberies have also increased slightly. Lanier cautioned against drawing conclusions from the homicide figures because it’s still early in the year and the total is close to last year’s number.

Property crime, however, is a different story. The Dupont Circle area has had 53 burglaries this year. At this time last year, it had 15.

“My mouth literally dropped when I looked at the numbers,” said Matt Rhoades, a Dupont Circle resident who edits Borderstan, a Web site that covers the Dupont Circle, Logan Circle and U Street neighborhoods.

Across the city, property crime is being driven in part by thieves who smash in back doors and squeeze through unlocked windows, then make off with cash, iPads, televisions and other valuables.

Some residents say they are steeling themselves for the warm-weather months, when criminals historically come out in force as more people spend time outdoors.

“We’re bracing for a bad summer,” said Anacostia resident Catherine Buell, who is worried about a sustained uptick in break-ins in her neighborhood. “I am genuinely concerned.”

The presence of crime can be deceptive, said Ward 2 Councilman Jack Evans, who represents neighborhoods including Dupont Circle and Georgetown. Police agree, noting bustling commercial strips where thieves make quick work of iPhones sitting on tables while their owners sip coffee.

“Everything feels safe, and you forget you’re in an inner-city neighborhood,” Evans said. In his ward, property crime has increased 46 percent this year over the same period in 2010.

“It’s widespread,” said Capt. Jeffrey Herold of the 2nd District, which has distinct boundaries from Ward 2 but includes Dupont Circle. Extra patrols and specialized units have been dispatched to areas that have experienced sharp increases in burglaries and other property crime, Herold said.

They are also trying to help residents protect themselves, saying many property crimes are acts of opportunity.

“If I see you walking down the street talking on the phone, I might stop you and say it’s not a good idea,” said Jacob Kishter, commander of the 3rd District, which includes Columbia Heights, U Street and Adams Morgan.

East of the Anacostia River, burglary emerged as a top crime issue in some neighborhoods last year. In the area that includes Historic Anacostia, burglaries and thefts continued to increase in the first months of the year.

In the surrounding neighborhoods, wallets are disappearing from school staffers’ purses and opportunists are stealing cars at gas stations — or making off with valuables people leave in their cars while pumping gas.

In an effort to raise awareness, 6th District Commander Robert Contee starred in a public service announcement video released last week, warning people to be careful while filling their gas tanks.

Cmdr. Joel Maupin of the 7th District, which includes Anacostia, said he’s seeing an increase in tires being taken directly off parked cars.

“It’s a bad economy,” Maupin said. “People are trying to get what they can get.”

Burglars rarely act as an organized “professional” ring, seasoned investigators say. Instead, they often act on their own or in pairs, selling stolen goods to pawn shops or trading them to a fencing operation in exchange for drugs.

And burglars tend to follow patterns, according to investigators. A burglar will hit an area over and over, gaining confidence each time, until he is caught. Once arrested, the break-ins slow down for a while until he is let out of jail — or until another burglar discovers the neighborhood.

Investigators say it’s not unheard of to arrest a suspect who is responsible for hundreds of burglaries. Increasingly, the perpetrators are teenagers, they say.

“We’ll see these upticks, then we’ll make some arrests and the stats will fall off the table,” Herold said.

Police in the Dupont area and elsewhere are still working to make those key arrests.

Criminals are also targeting retail stores and offices, police say. One office building on Connecticut Avenue in Van Ness has been broken into more than 10 times since June.

“They’re going into offices at night and stealing anything that’s not nailed down,” Herold said. Business owners in the Golden Triangle downtown area around the K Street corridor sent out an e-mail “crime alert” detailing a series of break-ins, including three in March in which thieves broke the front glass of storefronts.