Between 100 and 200 Occupy protesters marched through downtown Oakland, Calif. Friday night, smashing several car windows and the glass front of President Barack Obama's local campaign office, according to media reports.
The protesters had taken to the streets after being denied a permit to demonstrate at a monthly art walk, San Francisco ABC affiliate KGO-TV reported.
Several Obama campaign volunteers were working inside the office when the window was smashed with a brick, according to KGO. No one was hurt.
Twitter user David Colburn posted an image shortly after 9:30 p.m. showing a shattered glass window beneath an "Organizing for America" banner, with a large rock or brick still partially lodged inside.
"Smashed windows at Obama campaign's downtown #Oakland HQ," Colburn tweeted.
An Oakland police spokeswoman told the Contra Costa Times protesters started organizing around 9 p.m. She said police were following the protesters during their march.