A lack of security screeners due to the ongoing shutdown of the US government has resulted in airport terminals being shuttered in Houston and other cities.

NBC News reported yesterday that Terminal B at Houston’s Bush International Airport was closed to passengers due to a shortage of Transportation Security Administration (TSA) agents.

Under the shutdown — which is due to the refusal of President Donald Trump to sign budget legislation that doesn’t include money to build a wall on the southern US border — TSA agents are working without pay, and increasing numbers have called in sick or resigned.

The Houston terminal has been closed for two days, and airport officials are advising passengers to arrive for flights at least two hours in advance of flights in anticipation of delays at security checkpoints.

A similar closure occurred at Miami International Airport, and travellers have reported longer security lines at Atlanta’s busy Hartsfield-Jackson International Airport, USA Today reported.

TSA officials confirmed that worker absences have increased but insisted that “security standards remain uncompromised at our nation’s airports.”