Travelers encountered long lines and delays at security checkpoints at airports in Houston and New Orleans as a partial shutdown of the US Department of Homeland Security affected screening operations.

At Houston’s William P. Hobby Airport, wait times at standard checkpoints reached up to three hours, according to airport officials.

Authorities urged passengers to arrive four to five hours before their flights to allow extra time for security checks.

In New Orleans, a shortage of TSA staff also led to long queues, with some passengers warned waits could reach up to two hours.