Stills from footage of the Irish Republican Army (IRA) controlling the UK's border with Ireland have re-emerged after the government pledged to retain an 'invisible' border post-Brexit.

The shocking pictures, taken in February 1922, show members of the IRA armed with rifles, guarding the border between Northern Ireland and the South.

The video also shows IRA members stopping a car attempting to pass through the checkpoint and searching the driver, while another shot shows a soldier holding a machine gun while he smokes a cigarette.

Footage taken in February 1922 shows IRA members and guards armed with rifles, at the border between the North and South

It's believed to have been taken nearly 90 years ago in Clones, Co Monaghan, on the Irish border

The film is thought to have been taken in the town of Clones in County Monaghan, a small Irish town on the border of North and South.

At the time of filming tensions were high across Ireland, with the Anglo-Irish treaty establishing the North/South divide just a few months before, in December 1921.

The treaty established the Irish Free State, ending the War of Independence. It also created an opt-out clause for Northern Ireland, which it took.

It was negotiated and signed between David Lloyd George and Arthur Griffith.

The video shows the guards stopping and searching those trying to cross the border, at a time when tensions were high in Ireland

It's re-emerged as the UK government makes its proposals on the future of the border between Northern Ireland and the South, after Brexit

And just eleven days before the video was taken, a violent struggle at Clones railway station had resulted in the death of the local IRA commandant and four Ulster Special Constables, after the former had attempted to arrest the Ulster group.

The struggle happened after IRA volunteers attempted to ambush the Special Constabulary officers, ordering them to surrender as they travelled on a train through the County Monaghan train.

Relations between the pro-treaty Irish nationalists and anti-treaty Irish republicans only worsened as time went on, too, resulting in the June 1922 Civil War between the two sides.

It has re-emerged after Sinn Fein, the political wing of the IRA, questioned the future of the border when the UK leaves the European Union.

Ministers this week announced a 'soft border' with no border posts between the Republic and Northern Ireland, which was welcomed by the Irish Government.

Just eleven days before the video was taken, a violent struggle at a County Monaghan railway station had resulted in the death of the local IRA commandant and four Ulster Special Constables

The footage may be a stark reminder of the way the country used to be, as the future of the border hangs in the balance

A government 'position paper' rejected the idea of CCTV cameras or number plate recognition systems - instead saying that the current 'frictionless' arrangements should effectively stay in place.