MISURATA, Libya — Military forces loyal to Col. Muammar el-Qaddafi have been firing into residential neighborhoods in this embattled city with heavy weapons, including cluster bombs that have been banned by much of the world and ground-to-ground rockets, according to witnesses and survivors, as well as physical evidence.

Both of these so-called indiscriminate weapons, which strike large areas with a dense succession of high-explosive munitions, by their nature cannot be fired precisely. When fired into populated areas, they place civilians at grave risk.

The dangers were evident beside one of the impact craters on Friday, where eight people had been killed while standing in a bread line. Where a crowd had assembled for food, bits of human flesh had been blasted against a cinder-block wall.

The use of such weapons in these ways could add urgency to the arguments by Britain and France that the alliance needs to step up attacks on the Qaddafi forces, to better fulfill the United Nations mandate to protect civilians.