WASHINGTON — Police chiefs everywhere say that smartphone robberies are rocketing. They’ve offered cash rewards, set up decoy crews in subway stations and urged iPhone owners to be wary.

But the robberies keep coming. Now, police are expressing their frustration in plain terms, publicly asking regulators and wireless-network operators to allow stolen devices to be shut down remotely through unique identification numbers within them.

That could make it less likely that robbers would point a gun at a victim, knock someone down or steal someone’s smartphone, officials say, because the device’s resale value would plummet.

“This is a national issue,” D.C. Police Chief Cathy Lanier said Friday at a news conference. “We have done all we can at the local level.”

Lanier, who says electronics-related crimes has “clobbered” her department, wants wireless companies to use existing technology to let people who report stolen phones ask their service providers to shut them down using IMEI numbers, a unique registration akin to a fingerprint.

The United Kingdom uses a similar system, Lanier said, and police officials in the United States are asking federal regulators to urge the industry to implement it here.

Lanier has sent a resolution, endorsed by a group of other big-city police chiefs, to the Federal Communications Commission, asking the government to require mobile companies to “disable stolen mobile devices to deter the commission of these thefts.”

“It’s a simple way to alleviate it,” said Philadelphia Police Commissioner Charles Ramsey, president of the Major City Chiefs Police Association. “Why would mobile companies not want to do it?”

Officials are increasingly concerned about crimes involving mobile devices. District police say that about 40 percent of the nearly 500 robberies reported in 2012 involved cellphones, iPods or tablet computers. Metro officials reported a rash of snatch thefts last year, and undercover Metro officers arrested four would-be Apple device grabbers on Wednesday alone.

In New York, according to the office of Sen. Charles Schumer, D-N.Y., nearly half of the 16,000 robberies reported to police in the first 10 months of 2011 were of personal technology — mostly cellphones, with iPhones wildly popular. Other big-city chiefs report similar statistics.

“It’s a big problem here,” said Ramsey, who preceded Lanier as the District’s chief. “People have been attacked and knocked down, and thieves go through their pockets looking for these phones — not just for wallets or money.”

Police chiefs want the FCC to persuade companies to allow the shutdowns voluntarily or require it through regulation. Schumer supports the idea and has helped link Lanier and New York police with industry officials to discuss the issue.

In a telephone interview, Schumer — who sits on the Senate Judiciary Committee’s subcommittee on privacy, technology and the law — called electronics theft the top crime on New York’s subways. If the industry does not act, he said, he will push for a new regulation and might introduce legislation.

“We are pushing the regulators to do this,” Schumer said. “We’re pushing the companies to do this.”

The FCC acknowledges a problem but was noncommittal on the chiefs’ proposal. “Thefts of mobile devices are growing at an alarming rate, and we are actively working with public safety agencies and wireless carriers on ways to address this issue,” FCC Chairman Julius Genachowski said in a statement.

The proposal may meet stiff resistance from wireless carriers. “This isn’t the solution, because when you look at other countries that have tried this, it doesn’t work,” said Amy Storey, spokeswoman for CTIA, the national wireless trade group.

Police have found organized criminal outfits that ship phones overseas, according to CTIA general counsel Michael Altschul: In San Francisco, investigators found stolen smartphones that were shipped abroad, then reactivated or sold for parts.

“Cellphones are small and very valuable and easy to ship out of one country and resell in another that doesn’t have access to a database held by law enforcement or care to access the database,” Altschul said. “So the effectiveness of such programs are limited.”

Some stolen phones can be tracked using their SIM cards. But SIM cards can be replaced, leaving the phone usable, untraceable and valuable to would-be buyers. Lanier wants to target the market for stolen phones. “What’s going to stop this is stopping the profit,” Lanier said.

The idea, Lanier says, is not to combat the international export of stolen phones by organized criminals, but to discourage street crimes that put people at risk.

“I hear 15 stories or so every morning in my crime briefings,” Lanier said. “We are being clobbered with these robberies, and they’re looking for the same thing. They say, ‘Give me your purse. Now where is your phone?’ ”