London, Jan. 30 (ANI): A rebel group, calling itself the New IRA, is plotting a terror outrage as world leaders gather for a G8 summit in Northern Ireland, British counter intelligence agency MI5 chiefs have warned.

British PM David Cameron, US President Barack Obama and Russia's Vladimir Putin will be among those meeting in Enniskillen in June.

A Whitehall source said that they could not rule out some cowardly attack, the Sun reports.

Security chiefs warned that the renegade terror group plotting to wreck the summit has 700 members.

Five militant groups opposed to the Northern Ireland peace process have joined forces to form the New IRA.

The summit, at the five-star loch-side Lough Erne hotel in Enniskillen, County Fermanagh, will also be attended by German Chancellor Angela Merkel, French President Francois Hollande, Canadian PM Stephen Harper, Japanese PM Shinzo Abe and Italian PM Mario Monti, if he is re-elected next month.

The new group claimed responsibility for the murder of prison officer David Black last November, the report added. (ANI)