Airlines around the world are canceling flights due to the spread of the omicron variant, causing mass confusion among travelers in the holiday season.

According to the U.S. aviation tracking site FlightAware on Friday, nearly seven thousand flights scheduled from Thursday to Sunday have been canceled globally.

Demand has spiked for the holiday season, but there is not enough airline staff reporting to work because of COVID-19 infections or having to quarantine after coming in contact with a patient.

Flight delays are also occurring, with ten-thousand flights failing to take off on time around the world on Friday alone.

Amid staff shortages, Airlines for America, a lobbying group for the U.S. aviation industry, sent a letter to the Centers for Disease Control and Prevention asking to reduce the quarantine period for its members from the current ten to five days.