WALNUT CREEK, Calif. (KRON) – A lot of cleanup Thursday in the city of Walnut Creek after a band of protestors tagged 25 buildings with graffiti, including City Hall.

Most of the vandalism has already been covered but you can see some examples where someone sprayed BLM for Black Lives Matter, the other is an acronym slurring police officers, in fact, much of the vandalism targets police.

Spray painted over the City Hall sign the words pigs murder, many of the examples of last night’s unrest target police and reference the simmering anger over officer-involved shootings.

The name of the young man killed by police in Minnesota, Duante Wright, was scrawled on one building, others say kill cops.

Police say this was done by a crowd of 20-25 people wearing all black, their faces covered who marched down the center of the main corridors of the Business District starting around 9 p.m.

You can see it in action in this surveillance video as some break away to spray paint.

The cost of the destruction is estimated to run in the thousands, possibly tens of thousands of dollars — Many banks were also hit but so were several small businesses.

An investigation is underway.

While police say they don’t know if these protestors were affiliated with any group, a worker painted over graffiti that said Antifa was here.

Some say this is the wrong way for protestors to get their message across.

Police say one person was arrested after the fact after a vehicle stop on an outstanding warrant but at this point, they can not confirm that person was actually part of this civil unrest.