The rocket struck on the sideline of the pint-size soccer field, just inside a chain-link fence, where the children of Majdal Shams, a picturesque Druse Arab village in the Israeli-controlled Golan Heights, wait their turn to play, or just sit and watch.

On Sunday, a day after the deadly strike launched from Lebanon, a small crater about halfway between the goals was ringed by singed turf. A fortified concrete bomb shelter sat just steps away, now pockmarked by shrapnel, its entrance speckled with blood.

A siren warning of incoming rocket fire had sounded at about 6:18 p.m. on Saturday, but the strike arrived within seconds, local residents said, and there was no time to run.

Jwan Willy, 14, was standing by one of the goal posts at the time, watching a training session. He said he thought of running toward the shelter. But having grown used to the sirens during months of hostilities between Israel and Hezbollah, the Iran-backed Lebanese militant group, he stayed where he was.

Twelve children, Druse Arab boys and girls ranging in age from 10 to 16, were killed by the blast, and dozens more were injured and taken to hospitals. Israel blamed the attack on Hezbollah — which denied responsibility — and struck targets in Lebanon on Sunday, in what was seen as a restrained initial response. The Israeli military said the type of rocket used in the attack is Iranian-made and carries more than 50 kilograms of explosives. Hezbollah is the only group in Lebanon that possesses such rockets, the military said.