NEW FOOTAGE: Mystery solved - fighter jet flying low over east of Northern Ireland was an RAF Typhoon on NATO training mission - craft spotted from Carrickfergus and Belfast to Poyntzpass

One eyewitness described seeing the grey-coloured aircraft travelling roughly north-east to south-west over the north-western edge of Belfast Lough at about 6.30pm.

The initial roar of it passing was followed by another, even louder one after it had vanished from sight.

Others reported it over east Belfast.

One eagle-eyed resident of Poyntzpass, to the south of Banbridge, shared footage of the craft in the sky near his area too (it is the second of two video cips, above).

The clip preceding it was sent in this afternoon by a man in Banbridge itself, showing a clearer example of just how low and loud the flyover was.

Some observers said it appeared to be a Typhoon.

Among the comments online were these:

Neil Briscoe (@neilmbriscoe): “Ummm… did a Typhoon just go over my house in Belfast at pretty much flat-subsonic-chat?”

Martin Branney (@MartinBranney): “Fighter jet just casually flying over Belfast?!”

Kyle R.T. Flanigan (@kyleflanigan): “Well, that was a fighter jet over East Belfast.”

Grognard (@Grognardist): “Did Belfast just get buzzed by a fighter jet? Some roar! #Belfast.”

The News Letter has contacted the RAF to establish what the plane was and why it was flying so low, and is awaiting a response.

However, it has since emerged that this morning the Facebook page RAF Northern Ireland had issued the following message:

"Royal Air Force Typhoon is expected over HMS Caroline this evening at 18:30hrs arriving into Aldergrove at 18:50hrs.

"3(F) Sqn based at RAF Coningsby are conducting training in support of NATOs Air Policing Mission.”

If you have any more pictures / video of the craft, please email [email protected]