A new government policy document has raised concerns about the possibility of ‘lone wolf’ terror attacks within our borders.

The Department of Defence white paper - reported in the Irish Times - catalogues threats which could emerge over the coming years including: domestic terrorism, cyber attacks and organised crime.

The document once more raises the issue of Irish citizens travelling to the Middle East to join militant groups.

This policy white paper raises a number of concerns about terrorism in Ireland.

Chief among them is the government’s limited control over isolated attacks, similar to those in Paris and Brussels in recent months.

It once again highlights the threat of ‘radicalisation’ - and the number of Irish citizens who have travelled abroad to join groups like Islamic State.

That group has claimed responsibility for the Tunisian shootings, where three Irish people were among the 38 killed.

The document says other European countries’ experience shows the terror threat level can escalate rapidly, and can have a wide-range of sources or intensity.