An unknown number of British Airways flights have been delayed in what the airline has blamed on a "technical issue."
The social media team of the airline took to Twitter late Wednesday in an attempt to reassure passengers that steps were being taken to accommodate passengers affected by delays and cancellations.
On its website, British Airways also warned passengers that while it still planned to operate a full schedule on Thursday "there may be some knock-on delays to flights."
The U.K. flag carrier has suffered a series of bruising jabs to its reputation in recent months, including at least two computer failures, a pilot strike and a massive data breach.
Shares in British Airways parent company, International Airlines Group, slipped around 1% on Thursday morning. The share price is more than 14% lower on a 12-month basis.
One customer claimed on Twitter that while stuck on the tarmac in San Jose, California, late Thursday, the pilot had warned passengers that the "entire flight planning system is down."
In an emailed response to CNBC, the airline declined to elaborate on the nature of the problem but firmly rejected any suggestion that any of its systems had been hacked.