Iraqis hail their mobile phone network as one of the few achievements in the country's reconstruction, but the technology is also being used to detonate bombs that cause daily death and destruction.
Copying techniques employed by the attackers in the Madrid train bombings, the Bali bombings and recent blasts in Saudi Arabia, insurgents in Iraq are using mobile phones to set off car bombs and other explosions, US officials and experts say.
It is far from the only method being used, but since licences were awarded to set up the mobile network a year ago, and mobile phones became ubiquitous accessories in Iraqi cities, the technique has become common and reliable.
"There's definitely evidence that mobile phones are being used to detonate roadside bombs and car bombs," said David Claridge, a security specialist with the Risk Advisory Group who has worked in Iraq in recent months.
"I wouldn't say it's the single biggest contributor to the bombings, but it's a technique that they're employing."
Setting off a bomb using a mobile phone is fairly simple.
A call to the phone generates an electronic pulse that sets off the detonator or closes a circuit, triggering the bomb.
"It's not rocket science," John Pike of Globalsecurity.org, a Washington think-tank, was quoted as saying in a recent report by the US-based Homeland Security Group. "Cellphone detonators are pretty straightforward trade-craft."
Not only are they straightforward, reliable and relatively cheap, but conditions in Iraq make them particularly attractive.
Since the goal of the network was to provide service as quickly as possible, and make it accessible to as many people as possible, most subscribers use pay-as-you-go facilities, which make the individuals very difficult to trace.
Even if a call was made from one mobile phone to another to set off a bomb, telecoms experts question whether Iraqi operators would be capable of tracking the call quickly enough to help US troops and Iraqi police hunt down the perpetrators.
"With most Western mobile networks, it would be possible for intelligence agents to trace the call, or at least identify all calls made to that number at that time," said a London-based forensic security expert who asked not to be named.
"I'm not familiar with Iraq, but I can imagine that it would be more difficult to do such a thing there given the security situation and other limitations."
While Iraqis may face greater danger now that they have a mobile phone network, security consultants say that's just a fact of life - the technology brings benefits as well as risks and everyone in the world is potentially threatened.
"To deny access to mobile telecommunications at this stage would be counterproductive," said Claridge. "If insurgents in Iraq can't use mobile phones, they'll find something else."
Still, US troops have clamped down on mobile phone use at bomb sites to prevent follow-up blasts, the sort of attack that may have been used to kill 34 children in Baghdad on Thursday.
Locals and foreign journalists have had their phones confiscated by US forces for speaking from blast sites.
Military officials in Iraq also say they have employed high-tech mobile phone jamming equipment in some circumstances to stop potential attacks.