The MTA on Monday unveiled a new ad campaign encouraging riders to report hate crimes and other “bias-motivated” threats or graffiti.

The announcement — amid a surge in bigoted transit crimes — came on the 75th anniversary of the liberation of the Auschwitz concentration camp and just hours after NYPD arrested a man, for allegedly terrorizing a transgender woman on the subway over the weekend.

“It’s important to cut this behavior off, any kind of hate crime behavior,” MTA Chairman Pat Foye said at a press conference announcing the campaign.

“One of the lessons of the Holocaust is that it is important to take early signs of hate into account, to take them seriously.”

Each ad features an iconic MTA sign — such as the subway’s mosaics or Grand Central Terminal’s Metro-North track indicators — emblazoned with words like “kindness,” “respect” and “solidarity,” followed by guidance for reporting hate crimes or hate-related incidents to NYPD, state police or the MTA.

The new ads will run on 4,000 screens across the city’s subways and buses, and another 550 screens on Metro-North and Long Island Railroad, officials said.

Subway and bus hate crime reports increased 42 percent year-over-year from 2018 to 2019, according to MTA stats.

Transit officials hope the campaign will lead more New Yorkers to call violent crimes directly in to 911.

Riders can report lesser incidents such as graffiti or verbal threats to the MTA at 212-878-1000 and tips@mtahq.org, or to state police at 1-888-392-3644 or by texting “HATE” to 81336, officials said.