TSA agents at Newark Liberty International Airport may miss their first full paycheck Friday as a partial federal shutdown continues to affect Homeland Security staffing.

Officials say it affects about 1,000 TSA agents there, raising concerns that callouts could lead to longer checkpoint lines. Travelers were warned that staffing shortages could cause some people to miss flights.

Wait times Friday at Terminal A were about six minutes and staffing levels appeared normal.

Airports in Houston, Atlanta and New Orleans have already reported mass callouts, with travelers waiting between two and four hours in security lines.

Officials said the last paycheck for TSA workers was partial, covering only about 25% of normal pay. The full paycheck due Friday is not expected to arrive unless Congress reaches an agreement on funding for Homeland Security and immigration reform.

Nationwide, about 60,000 Homeland Security employees will not receive pay during the shutdown.

Travel officials urged passengers to check TSA wait times the same way they check flight status and to arrive earlier if lines begin to grow.

The partial government shutdown began in February after congressional Democrats and President Donald Trump’s team failed to reach a deal on legislation to fund the department through September.

Democrats are demanding changes to how immigration operations are conducted after the fatal shootings of U.S. citizens Alex Pretti and Renee Good by federal officers in Minneapolis.