A glitch in the computer system for Japan’s All Nippon Airways (ANA) led the airline to cancel numerous flights, reportedly leaving thousands of passengers stranded at Tokyo’s Haneda airport Tuesday. The ANA system’s malfunction reportedly affected reservations, ticket sales and boarding procedures across 48 other airports in Japan.

The problem was detected by the airline at about 8:20 a.m. local time (7:20 p.m. EDT Monday) and even though it was largely resolved in about three hours, ANA had cancelled more than 120 flights by the afternoon, Agence France-Presse (AFP) reported. More than 16,100 passengers’ travel plans were disrupted by 3:00 p.m. local time.

“The boarding procedure system recovered at 11:30 a.m., but we still have trouble with reservations and ticket sales,” ANA spokeswoman Natsuki Uota said Tuesday afternoon, according to AFP.

A report by the Associated Press (AP) said the airline admitted to web check-in, seat selection, new reservations, changes to reservations and payments being unavailable for domestic flights. ANA was investigating the reason for the system malfunction, AFP reported.

Four smaller airlines — Starflyer,  Airdo, Solaseed Air and Ibex Airlines — use the same system as ANA and they were also affected by the glitch, AP reported, citing Kyodo News agency.

A long three-day weekend ended Tuesday morning, meaning it was likely there were more passengers than usual.

A computer bug had affected ANA systems on Feb. 24 as well, leading to delays across 48 airports in Japan, the Asahi Shimbun reported.