The national carrier blamed the situation on an unusually large number of outbound passengers and the time it takes to check documents and online registration required by destination countries as part of their Covid-19 screening measures.
“The company has taken steps to rectify the problem and ensure no passengers miss their flights,” THAI said.
The apology came after a video posted by Facebook user Fah Walaiphan went viral on Friday.
The clip showed more than 1,000 passengers queuing to check in at THAI counters. The post included a message saying passengers will need to arrive at least five hours before departure to ensure they do not miss their flight.
She put the problem down to the shortage of staff, claiming that an airline employee grumbled that this issue was being ignored by the management “in the ivory tower”.
Fah followed up her initial post by saying she finally made it to the flight in time, but “the stress gave me a migraine that continued for many hours”.
She also said passengers whose flights were about to take off in half an hour were allowed to jump the queue so they could board in time.
“But you had to run like crazy because the time was so short,” the passenger said.