It's a war that's largely been forgotten. But Libya's descent into chaos after the fall of colonel Gaddafi six years ago has created a broken state - and a breeding ground for terrorism. It's been exploited by so called Islamic State who've been drawing in young men like the Manchester bomber Salman Abedi. He'd only recently returned from Libya when he blew himself up. Our Middle East correspondent Quentin Sommerville has been talking to another man from Manchester - a former friend of Abedi's - who travelled to Libya not to support the Islamic state group but to fight them. His report contains flashing images and scenes which some viewers may find disturbing.