Li Deng and her mother were driving on Interstate 680 on Sunday, when Deng turned off the freeway to exit at Berryessa.

That's when two large rocks suddenly hammered her SUV: one on the hood, followed by another into her car's windshield.

"Suddenly like bomb," Deng told KTVU. "And I saw my windshield cracked and we don't know what (was) going on because my mom and me are so traumatized."

The second rock shattered the windshield, sending small shards onto the pair's body and face, and even into Deng's mouth. When it was safe, Deng pulled over and called 911 and the CHP.

It wasn't the first time this had happened right around the Berryessa exit. After Deng posted the video on social media, others responded that something similar happened to them.

"(There were) other cases from people who said they saw this guy did that before," Deng told NBC Bay Area.

However, according to the CHP, none other than Deng have actually filed a formal report. That makes the CHP's job a little tougher, as information right now is sparse.

Deng's SUV had a dash cam, but it only shows a blurry man in a white shirt was the one who threw the rocks. CHP and Caltrans crews went out on Wednesday to survey the area, but it's not yet clear if they found anything suspicious.

In the meantime, Deng is warning drivers to be careful.

"This is a real person that is doing this on purpose to the public," she says. "So I want people to be alert so this won't happen again to any other innocent people."

To contact CHP with non-emergency information, dial 1-800-TELL-CHP (1-800-835-5247).

SFGATE has reached out to the CHP for updates.

Alyssa Pereira is an SFGATE staff writer. Email her at apereira@sfchronicle.com or find her on Twitter at @alyspereira.

