Police are investigating a dozen instances of vandalism where symbols resembling swastikas were drawn on buildings and street signs around Palo Alto and the Stanford University campus mainly between Dec. 29-31.

Palo Alto and Stanford police are working closely to investigate the incidents and identify suspects. Authorities have said most of the graffiti was drawn with a grease or oil-based pen.

“We take something like this very seriously,” Palo Alto police agent Ryan Brennan said “The detectives are doing their best to look for video evidence to find who did it.”

Brennan said some of the graffiti involved symbols that were likely meant to be swastikas, but were drawn incorrectly, with the arms facing different directions. Because these symbols were paired with the words, “No Jews allowed,” on a sign in the 700 block of Page Mill Road, police believe the vandals intended the symbols to be swastikas, Brennan said.

City police received a report about swastikas drawn on two street signs at Stanford Avenue and Bowdoin Street on Dec. 30. The same day, three swastikas on the exterior of a grocery store building were discovered in the 700 block of Emerson Street.

A vandalized city utility box in the 500 block of Page Mill Road was reported to police on Saturday.

A business in the 1000 block of Page Mill Road discovered vandalism on Dec. 30 but did not report the incident to police until Wednesday morning.

Bill Larson, public information officer for Stanford’s Department of Public Safety, said the agency got reports on Dec. 30 and Saturday of swastikas drawn on property at five locations.

“We do not know exactly when it occurred since the university has been on winter break closure since December 21st until today (Wednesday),” Larson said by email.

Swastikas were drawn in the following areas of Stanford: a pillar at the Main Quad, 450 Serra Mall; a sign in the Rodin Sculpture Gardens, 300 Lomita Drive; a sign in the 800 block of Campus Drive; a sign on Campus Drive at Escondido Road; a sign in the 800 block of Bowdoin Street; the Graduate School of Education building and the Clock Tower.

“The symbols are not technically swastikas,” Stanford Police Chief Laura Wilson said in a news release. “However, due to the similarity of the symbols to a swastika and the perception by witnesses that the symbols were intended to represent an object commonly associated with hate-based violence, the police are investigating the vandalism as a possible hate crime.”

Stanford President Marc Tessier-Lavigne said in a news release that the incidents are “profoundly troubling.”

“The university does not tolerate hate crimes, and our campus police are conducting a full investigation together with the Palo Alto police department,” Tessier-Lavigne said. “We have zero tolerance for such appalling acts. Stanford is a community that embraces civil discourse, where we value our differences and treat one another with respect.”

Palo Alto Councilman Cory Wolbach learned about the vandalism at Stanford Avenue and Bowdoin Street about 10 p.m. Monday night from a resident’s post on Facebook. He immediately went to the College Terrace neighborhood site to take photos of the street signs and remove the graffiti with alcohol wipes.

Wolbach said Tuesday that he hopes anyone who sees acts of hate will do whatever they can to stand in opposition.

“When we passed our resolution last month supporting an inclusive community and rejecting bigotry (including specifically calling out anti-semitism), some asked if it was necessary,” Wolbach said by email Tuesday. “Sadly, we now see how important it is. Palo Alto is a wonderful community, but not immune from bigotry and hate crimes.”

In December, the Palo Alto City Council approved a resolution reaffirming the city’s commitment to a “diverse, supportive, inclusive and protective” community in response to the rhetoric of President-elect Donald Trump attacking or mocking various groups, including undocumented immigrants, Muslim-Americans and Muslims, and gay and disabled people.

Anyone with information about the incidents is asked to call the city’s 24-hour dispatch center at 650-329-2413.

Anonymous tips can be emailed to paloalto@tipnow.org, sent via text message or voice mail to 650-383-8984, or submitted through the Palo Alto Police Department’s free mobile app, which can be downloaded at bit.ly/PAPD-AppStore or bit.ly/PAPD-GooglePlay.