Vandals sabotaged generators at President Trump’s Freedom 250 event, according to a spokeswoman — and fuel leached into underground water tanks, contaminating them.

A generator fuel line set up for temporary lights for a May 17 event was cut, causing fuel to seep into underground cisterns that collect rainwater under the Washington, DC, landmark, Freedom 250 spokeswoman Rachel Reisner told NBC News.

“Following the Freedom 250 team’s installation of temporary lighting on the National Mall, our equipment has been repeatedly targeted by vandals. The recent fuel leak was the direct result of that tampering,” she said.

“Upon discovering damage to a generator fuel line, Freedom 250 and our vendors mobilized within minutes, coordinated an immediate cleanup response, and fully remediated the site in close partnership with the National Park Service,” Reisner went on.

“We take our responsibility as stewards of the National Mall seriously and are working closely with the appropriate law enforcement authorities regarding these acts of vandalism.”

Earlier reports claimed that 30 gallons of fuel leaked under the National Mall, although sources told The Post the actual figure appeared to be far lower.

The leak did not impact drinking water.

The lights were installed last month ahead of “Rededicate 250,” a day of prayer and music from religious and political leaders including Secretary of State Marco Rubio, Defense Secretary Pete Hegseth, and House Speaker Mike Johnson.

On Monday, a “Mobile Command Center” owned by an environmental remediation company was spotted on the Mall at the site.

Freedom 250 was established by the Trump administration as a public-private partnership in the immediate run-up to the 250th anniversary of the adoption of the Declaration of Independence.

It is separate from America250, a nonprofit created by Congress 10 years ago and led by a bipartisan group of lawmakers and private citizens.

Administration officials said they are extra vigilant for vandals ahead of the upcoming semiquincentennial events.

“Just last week, an individual cut a fuel line to a light tower in an attempt to stop the great work being done to celebrate our nation’s 250th,” a spokesperson for the US Department of the Interior told The Post.

“This is unhinged behavior that will not be tolerated. To be crystal clear: We will not be stopped,” the DOI spokesperson added. “This administration continues to revitalize the city at record speed. Our nation’s capital has never been this safe and beautiful, and it’s all thanks to President Donald J. Trump.”

The National Park Service did not respond immediately to requests for comment.