Overtime costs for Oakland police and other city employees who have responded to protests the past few weeks reached $1.3 million as of last Saturday, city officials said.

The protests targeting police brutality have taken place in response to grand jury decisions in New York and Missouri not to charge police officers in the deaths of two unarmed men.

Assistant City Administrator Arturo Sanchez said in a letter to the Oakland community that police have responded to 14 protests over the past 18 days and officers' days off and holidays have been canceled.

Sanchez said, "For planning purposes, we must anticipate that the protests will continue; we are continuously monitoring the situation and we remain prepared to address protests in our community and provide mutual aid to neighboring cities when needed as well."

In fact, Sanchez said another protest was scheduled to begin at 5 p.m. Friday at 14th Street and Broadway and another protest is scheduled on Saturday.

Protesters have indicated that they will start from Berkeley at noon on Saturday and then march to 14th Street and Broadway, he said.

Oakland police have made a total of 209 arrests so far and other law enforcement agencies also have made a significant number of arrests in Oakland as well, according to Sanchez.

The protests in Oakland, he said, have involved "extremely fast-moving and unpredictable crowds," he said.

Sanchez said, "Many of the protests have occurred spontaneously and have moved from city to city, often coming into Oakland with very little notice, sometimes staying here and other times moving on to neighboring cities," Sanchez said.

He said, "Although the protests typically begin peacefully, small groups of people intent on vandalism and aggression have also been present; these groups have been largely responsible for most of the broken windows, graffiti and looting that has occurred, mainly in the late evening hours."

Sanchez said, "We have been particularly disturbed that in recent events, several peaceful protesters who have attempted to stop vandalism and destruction have been assaulted by members of the more violent contingent."

The fast-moving and unpredictable nature of crowd movements and the fact that crowds often splinter in different directions have made it difficult for the city to provide up-to-the-minute updates about the protests to the community, Sanchez said.

But he said, "We will continue to make every effort to let the community know when protests are expected, report any significant road closures or protest-related impacts, and provide a summary of any damage at the conclusion of each protest."