A hate crime investigation is underway after several nooses were found hanging from trees in the Lake Merritt neighborhood of Oakland, California.

Oakland Mayor Libby Schaaf said the nooses have been removed.

„Symbols of racial violence have no place in Oakland and will not be tolerated,“ she said in a statement on Twitter. „Several nooses were found on trees around Lake Merritt were removed and will be investigated as hate crimes. Reports that these were part of exercise equipment do not remove nor excuse their torturous and terrorizing effects.“

Schaaf went on to say: “We are all responsible for knowing the history and present day reality of lynchings, hate crimes and racial violence. Objects that invoke such terror will not be tolerated in Oakland’s public spaces.”

Read her statement:

Investigations underway in Southern California: Earlier this week, the FBI and California Attorney General’s Office will now be monitoring the investigation of a man found hanging from a tree in Palmdale, Los Angeles County Sheriff Alex Villanueva said at a news conference Monday.

Robert L. Fuller, 24, was hanging from a tree early Wednesday. Fire department personnel who responded to the scene determined he was dead, the Los Angeles County Sheriff’s Department said in a statement. Fuller’s death was described as „an alleged death by suicide.“

The Department of Justice and the FBI announced Monday they will be reviewing the hanging death of Fuller as well as the hanging death of 38-year-old Malcolm Harsch — both black males — 10 days earlier in San Bernardino County.