Iraq's armed forces have launched a major offensive to retake the northern city of Mosul from Islamic State (Isis), officials have said. The Iraqi military said it had recaptured several villages to the east of the city with the help of US-led coalition air strikes and Kurdish peshmerga forces.

The first part in a long-awaited operation, the offensive was launched on Thursday (24 Marc 2016) from the Makhmour area in the Ninevah province. The goal is to retake Mosul, Iraq's second-largest city, which has been held by IS since June 2014.

"The first phase of the Fatah [Conquest] Operation has been launched at dawn to liberate Nineveh, raising the Iraqi flag in several villages," said a military statement cited by the BBC. Officials say the aim is to seize the city within the year.

Mosul, which is around 220 miles north-west of Baghdad, became the terror group's largest city in its self-declared caliphate when it fell to Islamist fighters. An offensive to retake the city, which had a population of two million before IS rule, would be one of the biggest counterattacks against IS ever mounted by Iraq's armed forces.

The strength of Iraq's military continues to be questioned by analysts, however. Coalition and Iraqi officials estimate that 24,000 to 36,000 troops would be needed for the Mosul operation, Associated Press has reported. So far, only 2,000 to 3,000 Iraqi troops have been deployed at the Makhmour base.