OAKLAND, Calif. -- Oakland, California Mayor Sheng Thao's home was among several locations raided by the FBI Thursday morning, a source confirms to ABC San Francisco affiliate KGO.
The FBI said in a statement Thursday morning:
"The FBI is conducting court authorized law enforcement activity on Maiden Lane. We are unable to provide additional information at this time."
The details of the FBI's investigation remain unknown, but sources say the case involves the IRS and the U.S. Postal Service.
A neighbor visiting from San Diego told KGO that she was woken up by law enforcement banging on her door around 6 a.m.
A KGO crew on scene said there were several unmarked vehicles at Thao's house, and agents were seen carrying boxes from the location.
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Mayor Thao was supposed to appear at an event Thursday morning at 10 a.m., but she has canceled.
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This comes as organizers efforting a recall of Thao say they have enough signatures for it to appear on a ballot. They are also calling on her to resign as mayor.
Among the other locations raided is the home of Andy Duong of California Waste Solutions, who helped organize Mayor Thao's trip to Vietnam last year.
Andy Duong is the son of David Duong, the president and CEO of California Waste Solutions, whose house was also raided.
California Waste Solutions is Oakland's recycling vendor.