Iraq Takes IS Fight Into Sunni Heartland Amid Rising Tensions

Iraqi government forces are battling to expel Islamic State fighters from the vast Sunni heartland of Anbar province. They will likely have to fight without the Iran-backed Shi'ite militias who have proved crucial in the progress made so far in Iraq against the group also known as ISIS or ISIL. As Henry Ridgwell reports, there are growing concerns over sectarian violence and revenge attacks, with Tehran’s role in the conflict under the spotlight.