Image copyright Colm McAleer Image caption Queues stretched down staircases on Thursday night, according to passengers

Belfast International Airport has apologised again after passengers complained about long security queues.

Angry customers posted photos on social media which showed queues stretching down staircases on Thursday night.

Two Liverpool-bound passengers told BBC News NI that not all security lanes and bag scanners were in operation at the time.

An airport spokeswoman said extra lanes opened in response to a "high volume" of passengers and queues have cleared.

Long queues for security checks have been a problem at the airport on a number of occasions in recent months.

However, a regular traveller through Belfast International Airport told BBC News NI she had never seen anything like the queues on Thursday evening.

Mairead Comiskey from Armagh said she missed her 19:50 GMT flight to Liverpool, even though she had checked in her bags and joined the security queue more than an hour before departure.

"It was the first flight I have ever missed in my life," she said.

Ms Comiskey attended university in Liverpool and has been travelling there and back on a regular basis since 2009.

She said the "most infuriating" thing about her experience was that she saw two unstaffed lanes, despite lines of passengers stretched down airport steps.

'No communication'

Ms Comiskey was returning to work in Dubai after a Christmas break at home and needed to catch a connecting flight in England.

She managed to book on a later flight but complained of a lack of communication between airline and airport staff.

Colm McAleer from outside Omagh was also travelling to Liverpool and said he spent 80 minutes standing in a security queue.

He said he checked in his bag at 19:10 GMT but did not get through security until 20:30 GMT.

He claimed one bag scanner was not in operation and complained there was "no communication at all" with passengers, many of whom were trying to skip queues to make their flights.

A spokeswoman for the airport said it was a "very, very busy time of year" and a high volume of passengers arrived in the airport within a short space of time.

Missed flights

She said they plan for such scenarios and extra security lanes were opened in response.

She claimed that the queues "did move quickly" after that and all queues were cleared within a short period of time.

She added that they are contacting airlines to find out how many passengers missed flights during the period and will then make contact with the passengers involved.

Asked if the problem was connected to ongoing recruitment issues, she said: "The airport and our partner Wilson James are actively recruiting for the security team and we apologise for any inconvenience caused."

The airport has been repeatedly asking passengers to arrive two hours before their flight to ensure they have enough time to get through security.