IS 'hunts men for raising Iraqi flag in Mosul''

Mosul, Iraq's second largest city, has been controlled by so-called Islamic State since 2014

Islamic State militants have reportedly detained several men after Iraq's flag was raised in the city of Mosul, the group's main stronghold in the country.

A security source told the BBC the flag was flown from a bridge in the eastern Muthanna district on Tuesday night.

Anti-IS graffiti has also appeared on walls recently, as locals protest against the occupation of their city.

Mosul has been under IS control since 2014, but Iraq's government is planning to launch an offensive to recapture it.

• Mosul: Smuggled diary reveals life of fear under IS

• Is Mosul heading for a last 'apocalyptic' IS stand?

• Islamic State group: The full story

• IS and the crisis in Iraq and Syria in maps

Commanders say it could begin by the second half of October.

On Wednesday, Prime Minister Haider al-Abadi said the US was prepared to send more "trainers and advisers" to assist Iraqi troops during the battle.

Mr Abadi said they would not play a combat role, and that their number would be "reduced immediately after the liberation of Mosul".

One US official told the Associated Press that about 600 additional troops would be sent as the operation ramped up.

Mr Abadi met US President Barack Obama and Vice-President Joe Biden last week on the sidelines of the UN General Assembly in New York, though it is not clear whether they agreed to the deployment there.

Gen Joseph Votel, who oversees US forces in the Middle East, said in July that he expected to send additional troops to Iraq.

Some 4,600 US military personnel are already there as part of a multinational coalition against IS, providing air support, training, and advice to the Iraqi military, which was routed by IS militants in June 2014 as they overran much of northern and western Iraq.

Pro-government forces, including Kurdish Peshmerga and Shia-dominated paramilitary fighters, have retaken almost half of the territory since then.

But for Mosul, the largest occupied city in the "caliphate" proclaimed by IS, is likely to be the biggest yet.

The United Nations has warned that the humanitarian impact could be "enormous", and possibly affect up to 1.2 million people living in and around Mosul.