Robberies of portable electronic devices, particularly Apple Inc.’s popular iPhones and iPads, are climbing in New York City’s subway systems at the same time that cell phone service will be enabled in various stations around the city.

According to local reports, nearly half of such thefts occur on weekends.

Owen Monaghan, an assistant chief in the Police Department’s Transit Bureau, told The New York Times that 1,000 subway riders have been robbed this year through the end of August, versus a figure of 787 in the year-ago period – a 27 percent jump.

Monaghan added that the flurry of thefts has pushed up the broader subway crime rate by 17 percent from last year, to their highest level in six years.

“It’s electronic devices,” Monaghan told a committee meeting of the Metropolitan Transportation Authority, the agency that oversees the subway. “This spike concerns us.”

Typically, thieves often spring into action while a subway car is on a subway platform – as soon as the doors open, they seized the electronic products from people who are otherwise engaged in their music or reading. The culprits snatch the devices just prior to the doors closing and then flee the station,

The New York Times' story noted that one thief had been caught trying to steal cell phones 11 times.

The Transit Police said they're going to beef up subway patrols with plainclothes officers to attack the problem, particularly during rush hours.

“I can’t overstate the importance of crime prevention,” said Monaghan.

One subway commuter, 19-year old student Shahrazad Jebara, told the Times: “If I don’t have to use [my iPhone], I keep them it in my bag.”

Meanwhile, the introduction of cell phone service on a limited basis at some stations has some further concerned.

Subway rider advocate Bill Henderson told Metro New York: “It will encourage people to bring [iPhones and cell phones] out.”