Iraqis 'make gains against IS in Tikrit battle'
Iraqi government forces say they have retaken some districts around Tikrit in their fight to recapture the city from Islamic State militants.
A force of about 30,000 troops and militia are said to be attacking on different fronts, backed by air strikes from Iraqi jets.
A commander of Iran's Revolutionary Guards is taking part in the operation, a Shia militia commander told the BBC.
James Robbins reports.