TAIPEI (Taiwan News) – Starlux Airlines will cancel some flights to Bangkok and Ho Chi Minh City next month due to delays in the delivery of new planes, reports said Saturday.

The airline denied the cancellations were linked to surging fuel prices in the wake of the Iran War, per CNA. The company apologized and promised the passengers could change or cancel their tickets free of charge.

A passenger posted online that his Starlux flight to Thailand had been canceled, suggesting it was the result of fuel price increases. Other netizens wrote that fuel shortages at Bangkok’s airport might be responsible for the changes. Starlux denied all the theories, saying that the late delivery of new planes had forced them to adjust flight schedules for May on the Thailand and Vietnam destinations.

Taiwan’s main carriers hiked their fuel surcharges on April 7. Starlux said its added costs are NT$1,915 (US$60.33) for short-haul flights including to destinations in Southeast Asia, and NT$8,266 for long-haul flights.