OAKLAND (CBS SF) — Oakland city officials on Tuesday gave an update to the civil unrest that followed a peaceful student march and rally Monday that swelled to 15,000 community members.

Oakland Mayor Libby Schaaf and Deputy Police Chief Leronne Armstrong spoke Tuesday about the timeline of events which ended with a confrontation between police and a group of about 1,000 protesters who remained after the march ended. The standoff ended as object were thrown and police fired tear gas and rubber bullets to disperse the crowd.

Schaaf said the city and its law enforcement stands with their cause against police brutality; and because of that, the decision to use force to disperse people was not taken lightly.

“We’re in a moment of national anger about the abuse of police force and governmental authority. And so we take the use of force in this moment especially seriously.”

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Schaaf also recognized the vast majority of protesters were peaceful, and vowed to stop those who would seek to take advantage of the situation.

“We also are absolutely committed to public safety and we are doing what we can to prevent and hold accountable people who would do damage, who would commit violent acts, who would commit vandalism or theft in our beloved city.”

The mayor also urged people to report any instances of mistreatment by police officers and said the complaints would be thoroughly investigated.

Deputy Chief Armstrong said after the peaceful march and speeches at Frank Ogawa Plaza, in which his own daughter participated, a group of people remained in the area and began to march toward 8th and Broadway. At that point, officers started getting hit by rocks and bottles thrown at them and observed people preparing Molotov cocktails, Armstrong said.

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After multiple announcements that people were in an unlawful assembly and additional rocks and bottles being thrown, officers deployed tear gas and the group broke up into several splinter groups, Armstrong said, with the action coming before the 8 p.m. curfew.

As the curfew hour approached and multiple commands to disperse from the downtown area, Armstrong said police were compelled to begin breaking up the assembly.

“We continued to give those orders and allow people to leave who wanted to leave peacefully. Officers were engaged again with rocks and bottles and other things, at some point we did effect arrests.”

Armstrong said 60 people were cited and released, with no one going to jail. A handgun was also found in some bushes, along with rocks, bottles and boards.

The deputy chief added that the curfew allowed police officers to concentrate additional forces to prevent looting and vandalism of businesses.

Police spokeswoman Johnna Watson said Oakland has entered in a zero-tolerance stance for violence and destruction of businesses. “We absolutely cannot have the level of violence and damage that we’ve had in our city over the last five days,” said Watson.