It could happen again Thursday night.
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City crews have a lot to clean up. There's graffiti at 12th and Broadway and more damage like it all up and down the street.
Police estimate there were about 7,000 people there. It was a mostly peaceful group, according to authorities. But a few small splinter groups caused some problems.
PHOTOS: Protests spark in Bay Area after 2016 election
Demonstrators came out to protest having Donald Trump as the next president. Some say they were feeling sympathy for people who had to explain the election to children.
"Many of our teachers had to be with students who are scared to death of what may happen, Latino children, Muslim Arabic children," one demonstrator said.
There were some fires and fireworks Wednesday night. Police say they unleashed tear gas on some in the group when they started throwing things at officers.
Three cops were hurt, one is still in the hospital. Thirty people were arrested and charges ranged from vandalism to assault on an officer.
Another protest is set for Thursday at 5 p.m.
Click here for full coverage of the 2016 election.
Locally owned restaurant in Oakland damaged last night during angry protest against the Presidential election pic.twitter.com/7w8IWepSfO
— Amy Hollyfield (@amyhollyfield) November 9, 2016
.@oaklandpoliceca say 30 arrests made during last night's #Trump protest. Charges of assault on an ofc, vandalism, & more. #abc7now pic.twitter.com/YC9ZQ90em5
— Katie Utehs (@KatieUtehs) November 10, 2016
Oakland business owner trying to scrub graffiti off his window this morning. This is from last night's protest. pic.twitter.com/QZ2meuuvnn
— Amy Hollyfield (@amyhollyfield) November 10, 2016