At a time of heightened sensitivity to school safety, parents and school officials disagree over how to respond to toy guns and children who pretend to fire them.

Waiting in line for the bus, a Pennsylvania kindergartener tells her pals she's going to shoot them with a Hello Kitty toy that makes soap bubbles. In Maryland, two 6-year-old boys pretend their fingers are guns during a playground game of cops and robbers. In Massachusetts, a 5-year-old boy attending an after-school program makes a gun out of Legos and points it at other students while "simulating the sound of gunfire," as one school official put it.

Kids with active imaginations? Or potential threats to school safety?