OAKLAND (CBS SF/BCN) — Tony Cheung, who has owned New Tin’s Market in Oakland’s Chinatown neighborhood for 20 years, says he was stunned when he glanced at the wall outside his business and was confronted with racist graffiti.

It has been at least 15 years or more since his market has been targeted.

READ MORE: KPIX Reporters Remember Slain Security Guard Kevin Nishita; 'Just the Kindest Man'

“I noticed something written on the wall and was hesitant to do something — it shocked me,” Cheung told the East Bay Times

Oakland police said the incident was being investigated as a hate crime. The vandalism occurred between 5:30 p.m. Wednesday and 7:30 a.m. Thursday.

READ MORE: UPDATE: News Crew Security Guard Shot in Oakland Dies From Injuries; Photo of Suspect Vehicle Released

Officers were searching for and collecting any video footage that may have captured the offense. Anyone with more information was asked to please call the Oakland Police Department’s general crimes unit at (510) 238-3728.

Chinatown Chamber of Commerce president Carl Chan said that officials cannot “tolerate this ignorant and disrespectful behavior.”

MORE NEWS: Burlingame Shoppers Show Up for Small Business Saturday

“We must work together to combat these issues,” he said. “We do not tolerate this ignorant and disrespectful behavior that leads to senseless violence. It strikes me to my core and I am angered beyond words. Initiatives need to be made today without hesitation.”