People who were near the site of the attacks said that that still did not explain why the two men, both heavily armed, had not detonated their explosives inside the shopping center.

A dozen people interviewed all agreed that the government was too weak to prevent such assaults. Politicians and average Afghans questioned, for example, how the attackers had been able to move undetected through many checkpoints to reach the center of Kabul.

“The question is how come these terrorists are able to come all the way from the border to Kabul with all their ammunitions and stuff,” said Noor ul-Haq Uloumi, a member of Parliament who sits on its Defense Committee.

He said that corruption was probably involved. There are many reports of cases where guards have been bribed to enable criminals or insurgents to move through an area. “If we cannot eliminate corruption in the government and cannot make a government based on the rule of law to serve the people of Afghanistan, this corruption can bring many of such attacks,” Mr. Uloumi said.

Azizullah, 60, who sells music tapes from a booth that is only a few inches wider than his shoulders, made a similar point. “The government has police, intelligence guards and army soldiers in all the crossroads, so how can these people get in?” said Mr. Azizullah, who like many Afghans uses one name.

Corruption is so pervasive that the United Nations Office on Drugs and Crime reported on Tuesday that interviews with 7,600 Afghans across the country led to the conclusion that the bribes people pay account for nearly a quarter of the country’s gross domestic product.

Some Kabul residents speculated that Monday’s attack had been engineered by the United States to justify staying longer in Afghanistan. “Maybe the Americans are behind it,” said Zia-ul Haq, 22, who works in a stationery store a few feet from the site of a second major attack on Monday, in which a militant driving an ambulance blew himself up. “Otherwise, how could they have come through all these security checkpoints?”