Philadelphia International Airport has joined other airports around the country in refusing to play a video from Homeland Security Secretary Kristi Noem that blames Democrats for the federal government shutdown.

“The video has not been played on airport monitors,” an airport spokesperson said in an email. “The City of Philadelphia Department of Aviation, owner and operator of Philadelphia International Airport, does not accept or display materials that are political in nature in its facilities.”

Airports in New York, Chicago, Phoenix, Las Vegas, and elsewhere, including in some Republican-controlled areas, have refused to play the video because of restrictions on political messaging.

Federal government agencies under President Donald Trump have been pushing messages blaming Democrats or the “Radical Left” for the government shutdown that began Oct. 1.

Ethics experts argue that the messages violate the 1939 Hatch Act, which restricts certain political activities by federal employees.

In the video, Noem says that the “top priority” of the U.S. Transportation Security Administration, which is overseen by the Department of Homeland Security, is to make sure travel is efficient and pleasant while keeping passengers safe.

“However, Democrats in Congress refuse to fund the federal government, and because of this, many of our operations are impacted, and most of our TSA employees are working without pay,” Noem says.

The TSA has more than 64,000 employees, and around 61,000 are required to continue working during the shutdown.

A DHS spokesperson said in a statement to The Associated Press: “It’s unfortunate our workforce has been put in this position due to political gamesmanship. Our hope is that Democrats will soon recognize the importance of opening the government.”

To get their votes to end the shutdown, Democrats say they want to extend tax credits that reduce the cost of healthcare premiums for the Affordable Care Act. The tax credits expire in December, but Democrats want them extended before enrollment begins Nov. 1.

— The Associated Press contributed to this article.