Ryanair has reported a 10% increase in the number of passengers it carried in September, despite the airline cancelling thousands of flights due to rostering problems.

Ryanair said it carried 11.8 million customers in September, up from 10.8 million the same time last year.

The airline also said its load factor - how many seats it fills on each flight - increased to 97% from 95% in September of last year.

"These figures include the 2,100 flight cancellations announced for September and October. We have now refunded/re-accommodated 98% of customers who were impacted in September and October," Ryanair's chief marketing officer Kenny Jacobs said.

"We again sincerely apologise to our customers for these deeply regretted cancellations," he added. 

Ryanair said last week that it was cutting back its growth plans for the first time in years to help alleviate the roster issues at the carrier.

The airline said the slower rate of growth will slightly reduce its traffic this year and next. 

"Our monthly growth from November 2017 to March 2018 will slow from 9% to 4%. Our full year traffic of 131 million will now moderate to 129 million, which is 7.5% up on last year," Ryanair said. 

"By slowing our summer 2018 fleet growth from 445 to 435 aircraft, we expect traffic to March 2019 will slow from 142 million to 138 million, a 7% rate of growth," it added.

Shares in the company closed 2.01% higher at €17.22 in Dublin trade today.