“They abandoned us completely,” said Rob Chabot, the owner of Mobile Eye Care Solutions, along South Florissant Road, where episodes of violence flared on Monday. “They sacrificed Ferguson. For what cause? I don’t know.”

In a news conference here, James Knowles III, the mayor of Ferguson, was also critical of the state’s response. “Unfortunately, as the unrest grew and further assistance was needed, the National Guard was not deployed in enough time to save all of our businesses,” he said.

By Tuesday afternoon, the police reported that there had been 21 fires in and around Ferguson, at least 150 gunshots and damage to 10 police cruisers. At times, officials said, firefighters had to retreat from battling fires because of gunfire and objects being thrown all around.

Just as law enforcement officials were criticized for being too aggressive in August, they were facing questions on Tuesday over whether their approach this time was too tame. Chief Jon Belmar of the St. Louis County Police and other officials defended their response, saying that they took steps to de-escalate the situation but that the magnitude of the violence was beyond their control.

Chief Belmar said the initial, hands-off tactics by the police were intended to allow protesters to demonstrate peacefully, but he said that the situation ultimately grew so unstable that it required a more forceful approach.

“I don’t think we were underprepared, but I’ll be honest with you, unless we bring 10,000 policemen in here, I don’t think we can prevent folks that really are intent on destroying a community,” he said. But he admitted that despite months of preparation and training, and a buildup of manpower, equipment and technology, he had not foreseen the chaos that ultimately unfolded.

Among the more than 60 people arrested, on various charges including second-degree burglary and arson, most were Missouri residents — a shift, some here said, from the unrest of the summer.