The next morning, a driver took a group of foreign journalists to an area known as the Friday market, which appeared to have been the site of a riot the night before. The streets were strewn with debris, and piles of shattered glass had been collected in cardboard boxes.

A young man approached the journalists to deliver a passionate plea for unity and accolades to Colonel Qaddafi, then slipped away in a white van full of police officers. Meanwhile, two small boys surreptitiously offered bullet casings that they presented as evidence of force used on protesters the day before.

At another stop, in the working-class suburb of Tajoura, journalists stumbled almost accidentally into a block cordoned off by low makeshift barriers where dozens of residents were eager to talk about a week of what they said were peaceful protests crushed by Colonel Qaddafi’s security forces with overwhelming, deadly and often random force.

A middle-age business owner, who spoke on condition that he be identified only as Turki, said that the demonstrations there had begun last Sunday, when thousands of protesters inspired by the uprising in the east had marched toward Green Square.

Suddenly, he said, they found themselves caught between two groups of double-cabin pickup trucks without license plates, about 40 in all. Men in the trucks opened fire, and killed a man named Issa Hatey. He said neighbors had renamed the area’s central traffic circle “Issa Hatey Square” in his memory.

He and other residents said that over the past week neighbors had been besieged by pickup trucks full of armed men shooting randomly at the crowds, sometimes wounding people who were sitting peacefully in their homes or cars. At other times, they said, the security forces had employed rooftop snipers, antiaircraft guns mounted on trucks and buckshot, and the residents produced shells and casings that appeared to confirm their reports. Turki said that on one day he had seen 50 to 60 heavily armed men who appeared to be mercenaries from nearby African countries.