The Transportation Security Administration said it has screened the lowest daily number of airline passengers since May 11 amid the spike in US COVID-19 cases.

The 1.345 million airline passengers screened on Tuesday was down about 33 percent over the same day in 2019 when 2.04 million traveled, the TSA said.

Last month, Southwest Airlines warned that the spread of the Delta variant of COVID-19 had hit bookings and increased cancellations.