New York City Department of Sanitation trucks brimming with sand are stationed outside Trump Tower in Manhattan, serving as a protective barrier on a heated Election Day, according to reports.

A law enforcement officer told TMZ the purpose is to help protect the Republican presidential nominee from potentially explosive attacks.

Reuters and TMZ referred to them as sanitation trucks, but the city’s sanitation department declined to comment to The Washington Post.

The New York Police Department did not immediately respond to a request for comment.

A sanitation representative told TMZ the the department had also parked sand-filled trucks outside New York’s Peninsula Hotel, Hilton Hotel and Jacob K. Javits Convention Center. All three buildings are expected to be used for official campaign events on election night.