Newspaper headlines underlined the frustration felt by many Indians, with one saying, ""Our Politicians Fiddle as Innocents Die." During the protest outside the Taj Mahal Hotel, some demonstrators even carried placards saying they wished the politicians had been killed in the attacks.
Public anger was also fuelled by reports that the Indian government had received warnings earlier this month of an impending terrorist attack in Mumbai, including information from U.S. intelligence sources.
Even before the claim, anger over the coordinated terrorist attacks was exacerbating tensions between the two nations, both nuclear-armed states, as investigators try piece together how so few attackers could have wreaked so much carnage in India's largest city.
Some fault Pakistan, claiming it harbored some of the terrorists, and Indian officials continue to beat the drum about their neighbor's involvement.
Pakistan has been firm in its denial that its government had any connection to the men at the center of the 60-hour siege.
Husain Haqqani, the Pakistani ambassador to the United States, told ABC News' "This Week" that while the gunmen may have come from Pakistan, its government had no ties to the assailants.
"That they are harbored by Pakistan is plain wrong," Haqqani said. "The important thing is that the government of Pakistan, the state of Pakistan, the military of Pakistan and even the intelligence services are not directly involved."
Haqqani said the Pakistani government was going the extra mile to let India know "we feel their pain."
"The point we must remember is that we should not see this heinous act in the context of India-Pakistan relations," Haqqani said. "We should see it in the context of international terrorism. There are terrorists that have trained in all countries of the world, secretly. They are non-state actors. I don't think that this is the time for India, or anybody in India to accuse Pakistan. It's time to work with Pakistan."
Haqqani added that Indians should question their own government about whether the Mumbai attack could have been prevented.
"Intelligence failure? I think people have to look closer to home for that," he said.
The broader intelligence value of the captured suspect, a 21-year-old Pakistani man with a fourth-grade education, remains unclear, but he could bolster arguments from within India that the plot had Pakistani roots.
India hasn't outright blamed Pakistan for what happened, but one official said the government plans to increase security along its border. It remains unclear what that means and so far there have been no reports that it's occurred.
If India posts troops along its border with Pakistan, Haqqani said Pakistan will be forced to do the same.
It could be damaging to the United States if Pakistan turns its attention and troops to India, distracting it from Afghanistan, al Qaeda and the war on terror. Militants recently have gained strength in Pakistan.
"Pakistan and Afghanistan became the focus of jihad central many, many years when they were all fighting the Soviets," Haqqani said. "So these people have roots in some remote parts of our country. They have spread those roots. Some of the efforts in the war on terror have not been successful.
"Our dictator, [former president] Gen. Musharraf did not do the right thing to eliminate the terrorists," he said. "But the new government is making it's effort and our intelligence services are far better prepared.