OAKLAND (KGO) -- Many of those arrested for looting in Alameda County over the weekend were from out of town, revealed Oakland's police chief in a press conference Monday.

"Many were coming actually from, surprisingly, the Stockton, Merced, southern area and coming in very organized fashion... 15, 20, 30 cars at a time, hitting as you've seen different shopping malls, different areas," said Interim Police Chief Susan Manheimer.

Oakland Mayor Libby Schaaf said 60 people were arrested Sunday who were "clearly engaged in serious illegal activity." She said many of the alleged looters had targeted businesses in East Oakland and Fruitvale.

"These attacks last night were to business owners that are already vulnerable to this pandemic and that are the only services and beloved resources for these communities that are already suffering. So it was extremely painful," Schaaf said.