It goes like this: Boy meets girl. They exchange glances and text messages, the limit of respectable courting here. Then boy asks girl’s father for her hand. Dad turns him down. Boy goes to girl’s house and plants a bomb out front.

The authorities call it a “love I.E.D.,” or improvised explosive device, and it is not just an isolated case. Capt. Nabil Abdul Hussein of the Iraqi national police said that six had exploded in the Dora neighborhood of Baghdad alone in the past year.

“These guys, they face any problem with their girlfriends, family, anyone, and they’re making this kind of I.E.D.,” Captain Hussein said.

There have been no reported deaths or injuries from the devices used in this way, in Dora or elsewhere. “Usually they’re putting them in front of the doors of their houses, not to kill, but to scare them,” Captain Hussein said.

After six years of war, Iraq is a society with a serious anger management problem. That, along with a lot of men with a lot of experience fashioning bombs and setting ambushes, makes for a lethal mix.

The police say that many of the men are former insurgents who are no longer trying to kill foreign troops but who have an array of bomb-making skills and a stash of TNT.