Subsequently, on 18 May the IDF launched Operation Rainbow with a stated aim of striking the militant infrastructure of Rafah, destroying smuggling tunnels, and stopping a shipment of SA-7 missiles and improved anti-tank weapons. A total of 41 Palestinian militants and 12 civilians were killed in the operation, and about 45–56 Palestinian structures were demolished. Israeli tanks shelled hundreds of Palestinian protesters approaching their positions, killing 10. The protesters had disregarded Israeli warnings to turn back. This incident led to a worldwide outcry against the operation.