A hate-crime investigation has been launched in Northern California after several nooses were found hanging from trees. Oakland Mayor Libby Schaaf said Wednesday that several nooses were removed from trees in the Lake Merritt area, adding: “Symbols of racial violence have no place in Oakland and will not be tolerated.” The Oakland Police Department told CNN that a total of five ropes were discovered attached to various trees during a search. The department said evidence has been handed over to the FBI. During an initial investigation, residents are said to have claimed the ropes were used for exercise, but Schaaf has dismissed that excuse. “Reports that these were part of exercise equipment do not remove nor excuse their torturous and terrorizing effects,” she said, adding: “We have to start with the assumption that these are hate crimes... We cannot take these actions lightly, we have to take them seriously.”