I'm reading one of Paul Theroux's books, which was published in 2006 during the height of the second Gulf War, and there is a passage in it in which the author apparently claims the activity described in the title of this question:
“We were a Turkoman family in Iraq,” a woman said to me, and introduced herself as Professor Emel Dogramaci of Cankaya University. “We were powerful in Kirkuk.”
“We know Rumsfeld!” the woman said, snorting at the name. “He was supporting Iraq during the Iran-Iraq War. He was supporting Saddam! He was telling us to do the same!”
From their home in Kirkuk her family had observed Donald Rumsfeld paddling palms and pinching fingers with Saddam, and selling him weapons, among them land mines. The Iranian response was to send small children—because children are numerous, portable, and expendable—running, tripping into the minefields to detonate the bombs with their tiny feet, to be blown to pieces.
Theroux, Paul. Ghost Train to the Eastern Star: 28,000 Miles in Search of the Railway Bazaar (p. 61). Houghton Mifflin Harcourt.
Several people have disputed this claim, saying it is extremely unlikely that this happened. I have no information that it did or didn't, and although there is a a documented case of a 12-year-old voluntarily blowing up a tank in the Iran-Iraq conflict, killing himself (see Mohammad Hussein Fahmideh), I can't find anything elsewhere about a more general version of this disturbing practice, if it existed. Note that a young Iranian acquaintance is shocked and horrified to hear the suggestion, though he acknowledges that Fahmideh is touted as a hero in Iran even today.
Addendum I see a couple of excellent answers, but Theroux seems to imply that smaller children were involved ("running, tripping into the minefields to detonate the bombs with their tiny feet"). Is he perhaps misinformed, exaggerating for effect, or being somewhat disingenuous?