Three weeks into the partial government shutdown, airports and their workers are beginning to feel some serious pain.

At least one major airport has had to temporarily shutter a concourse because of staffing issues related to the shutdown. Others are opening food pantries to support the Transportation Security Administration staffers working without pay.

Miami International Airport closed one of its concourses for half the day on Saturday. Airport officials said they plan to do the same on Sunday and Monday out of concerns they wouldn’t have enough employees to operate all the security checkpoints.

That decision was made after an unusually high number of workers called in sick. The number of illness-related absences has doubled since the shutdown started, Miami officials said.

That jump is probably related to a national trend of TSA employees calling in sick to protest having to work without pay during the shutdown.

Miami International Airport spokesman Greg Chin said the decision to close parts of the airport was a “precautionary measure to optimize staffing” during peak times when large numbers of cruise-line passengers leave the city. The 10 to 12 affected flights will depart from other terminals.

Airports across the country are facing staffing shortages, according to statistics released by the TSA. On Friday, 5.6 percent of the administration’s 51,000 workers did not show up for work, compared with 3.3 percent who took unscheduled absences on Jan. 13, 2018.

But the impact of those absences on fliers and airport security has been hotly debated. After several news outlets published stories featuring long lines at airport security, the Department of Homeland Security pushed back, calling the reporting “fake news.” Officials say there have been no major delays, and no impact on national security.

On Friday, the TSA released data showing that virtually all of the 1.96 million passengers who flew on Friday cleared security within 30 minutes. About 95 percent waited less than 15 minutes, according to the data.

“Security standards remain uncompromised at our nation’s airports,” TSA spokesman Jim Gregory wrote in an email. “We thank the public for their continued support and acts of kindness.”

Airport officials, however, warn that the situation could get much worse if the shutdown isn’t resolved soon. Many say they’re drafting contingency plans to deal with a shortage of TSA workers, like shutting certain security checkpoints or supplying extra staff temporarily to run bins or perform other nonsecurity functions.

“Despite the shutdown, TSA security officers continue to do a great job of effectively and efficiently screening passengers and bags,” said Christopher Bidwell, senior vice president of security for Airports Council International-North America, an association that represents the owners and operators of airports. “But we’re very concerned that the situation of government workers working without pay is unsustainable.”

While the shutdown’s effects on airport operations do not appear to be widespread right now, smaller airports could be most vulnerable, because even a few absent TSA workers could cause long security lines.

Some aid groups are also stepping up to provide groceries and other necessities to cash-strapped security screeners.

Tampa International Airport is working with local partners to launch a food pantry for federal workers starting Monday.

“At our airport, we’re not seeing at this point operational impacts like they are at other airports,” said spokeswoman Janet Scherberger. The food pantry, she said, would help keep people motivated to show up.

“We want people to keep coming to work,” she said. “We need them to keep the airport running.”

About 80 TSA workers from the Raleigh-Durham International Airport visited a food pantry last week, according to Kathleen Lee, director of services for the White Oak Foundation, which organized the assistance. Lee said that going forward, the organization had designated two days a week for TSA workers to pick up food “as long as it’s productive and necessary.”

Other airports are looking at ways to support employees, like bringing in utility companies to give workers more flexibility on paying their bills or a credit union that could help provide loans.

That’s the goal in Tampa, where the food pantry will also offer bus passes to help employees get to work during the shutdown.

“This is really a response to the need of people who we work alongside everyday and aren’t being paid, and so it’s about doing the right thing for people who are part of the airport family,” Scherberger said.

TSA Administrator David P. Pekoske also announced Friday that workers who manned checkpoints on Dec. 22 would be paid for their work that day and would receive a bonus for working through the busy holiday season.

“While I realize this is not what you are owed for your hard work during pay period 26 and what you deserve, I hope these actions alleviate some of the financial hardship many of you are facing,” Pekoske tweeted.