Surging jet fuel prices, driven by escalating Middle East tensions and a United States blockade on Iranian ports, have triggered a wave of flight cancellations on routes from China to Southeast Asia, disrupting travel plans for millions ahead of the May Day holiday.

Multiple Chinese and regional carriers, including Air China, China Eastern, Spring Airlines, China Southern, and Malaysia-based AirAsia, have scrapped or suspended services to popular destinations such as Bangkok, Phuket, Vientiane, and Kuala Lumpur.

Data from Hangban Guanjia, a flight-tracking platform, shows that since April 1, all flights on several routes, including Xi'an-Phuket, Chongqing-Phuket, and Yantai-Bangkok, have been canceled, with full cancellations already confirmed through May.

Oceania routes have also been hit hard, with cancellation rates on services such as Wuhan-Sydney and Guangzhou-Darwin exceeding 50 percent in April and expected to climb further in May.

The disruptions stem from a sharp spike in crude oil prices. On April 13, US crude surged 8 percent to top $104 a barrel after Washington announced a blockade on Iranian ports following failed negotiations.

Heating oil, a key benchmark for aviation fuel, jumped 10 percent. Fuel typically accounts for 30 to 40 percent of an airline's operating costs.

The International Air Transport Association has warned that even if the Strait of Hormuz reopens, global jet fuel supplies may take months to normalize.

AirAsia has raised long-haul fares by up to 40 percent and fuel surcharges by 20 percent, while also cutting 10 percent of flights. Australia's Qantas and Indonesia have likewise announced fare hikes and surcharge increases.

For Chinese travelers, the cancellations are particularly frustrating. Southeast Asia had been seen as a cost-effective alternative after travelers ruled out the Middle East for safety concerns and Europe and Africa for distance and price.