Vandals scrawled swastikas on the outside of Union Station, the central hub for regional train transportation in the nation’s capital.

The graffiti was discovered Friday, one day after International Holocaust Remembrance Day, with crude Nazi symbols marked on columns across the front of the massive building and several clustered around the escalator entrance to the underground D.C. Metro.

Metropolitan Police Department Chief Robert Contee said the investigation would be led by the Amtrak Police, who handle security for the building. But Contee indicated that investigators were looking at some of the several people experiencing homelessness who frequently camp around the building.

“It appears it may be one of our unhoused residents who did this, based on some information that has been revealed,” Contee said. “The person who did this … could very well have some mental health challenges.”

A security guard on the scene pointed out that several of the swastikas were in spots that were in full view of the building’s security video cameras.

Amtrak spokeswoman Kimberly Woods said an investigation is underway. “Amtrak strongly condemns this act of hate and will work with our landlord, USRC and their lessor to remove these symbols as quickly as possible,” Woods said in a statement.

By midday, staff had begun to cover the swastikas with sheets of white paper secured by blue tape.

District of Columbia Mayor Muriel Bowser called the incident “both shocking and unsettling.”

“This antisemitic and hateful symbol has no place in our city, and we stand united with the members of our Jewish community against antisemitism in all its forms,” she said.

Bowser said Union Station had a team of experts working to remove the graffiti.

The Jewish Federation of Greater Washington posted a statement on Instagram, calling the timing “particularly offensive” and added, “This anti-semitic and hateful symbol has no place in our society.”

It is unclear whether the connection to International Holocaust Remembrance Day was intentional. Contee said his department had been in touch with local Jewish community leaders.

(AP)