The low-cost carrier on Monday apologised to passengers after eight return services between Melbourne and Sydney and Denpasar were cancelled since the beginning of the month.
"Unfortunately, our Boeing 787 fleet has been impacted by a number of issues, including a lightning strike, a bird strike, damage from an item on the runway and delays sourcing a specific spare part for one of our aircraft due to global supply chain challenges," a Jetstar spokesman said.
The Qantas subsidiary said it had accommodated a majority of affected passengers and was working to find alternatives for about 200 more.
Furious passengers took to social media to vent their frustrations after last-minute flight cancellations to and from Indonesia, Thailand and Japan.
Some passengers reported having multiple flight cancellations in the same day, no alternative flights for up to five days and limited access to customer service.
"My elderly parents stranded in Bangkok with no help or guidance from anyone!" Melbourne woman Filiz Tigli tweeted.
It comes after recent reports of Australian Jetstar passengers being stuck at Tokyo's Narita Airport overnight without food and water due to strict COVID-19 border controls.
There were also reports of domestic flight delays and cancellations across Australia on Monday from Jetstar and Qantas passengers.
"Flight from Melbourne to Sydney today for daughter to attend funeral cancelled twice, the 2nd time at 10.20 last night. No other Jetstar flight available for today. No way to contact the airline after 10pm. Qantas and Jetstar are a joke. No credibility," one woman known as "Margie" tweeted.
Qantas apologised last month after complaints from passengers who had flights delayed or cancelled, faced long queues at airports and lost baggage in recent months.
Qantas Group faced more pressure on Monday, with Tasmanian Premier Jeremy Rockliff raising concerns the island state had been disproportionately hit by flight reductions than elsewhere in Australia.
Mr Rockliff said he had written to Qantas and Virgin Australia and had spoken with Qantas CEO Alan Joyce last week.
"I have followed up again formally with both airlines today, and it's my clear expectation that both airlines respond as soon as possible and clarify the situation."
The national carrier is the subject of an ABC investigation to air on Monday, with dozens of Qantas staff speaking about their concerns for the airline's reputation.
Next week Qantas, Emirates and Etihad face potential delays as baggage handlers set take strike action.
Ground handlers from Dnata, who are contracted to Qantas and more than a dozen other carriers, will walk off the job for 24 hours next Monday.
The industrial action was agreed to by Dnata workers on Friday, with about 350 crew to strike.
Dnata will appear before the Fair Work Commission on Tuesday in a bid to stave off the strike.
