Some 4000 Iraqi volunteers are being airlifted to an embattled city west of Baghdad to bolster government forces locked in a battle with Sunni militants there.

Around 2500 of the volunteers arrived in Ramadi, 70 miles west of the capital, on Friday and were joined by another 1500 yesterday, said Gen Rasheed Flayeh, the commander of operations in Anbar province. Most are Shi-ites, answering a call from the country's top Shi-ite cleric, Ayatollah Ali al-Sistani, to defend Iraq from militants from the Islamic State (Isis) extremist group.