Iraq has declared that its forces had retaken the northern city of Tal Afar and the surrounding region, in another major victory over the so-called Islamic State group.

IS, which seized nearly a third of Iraq in 2014 in a humiliating defeat for the army and police, now controls barely 10% of the country, according to the US-led international coalition ranged against the jihadists.

The fall of Tal Afar, located in the northern province of Nineveh, deprives IS of what was once a key supply hub between its territory in Iraq and neighbouring Syria.

After a 12-day battle by Iraqi forces backed by coalition air strikes and Shia paramilitary fighters, Prime Minister Haider al-Abadi announced that Tal Afar had "regained its place in the national territory".

He vowed to liberate "every inch of Iraqi territory" from the group.

"We say to the criminals of IS: wherever you are, we're coming to liberate it and you have no choice but to die or surrender," Mr Abadi said.

The full recapture of Nineveh province comes weeks after Iraqi forces ousted the jihadists from the provincial capital Mosul, three years since IS declared a self-styled "caliphate" straddling Iraq and war-torn Syria.

As promised by Iraqi officials, the victory also comes in time for the Muslim feast of Eid al-Adha, which starts today for Iraqi Sunnis and tomorrow for Shias.

Andrew A Croft, deputy commander of the coalition, said the speed with which Tal Afar and surrounding areas were retaken was a "positive sign".

"It showed the Iraqi forces' abilities against IS in Iraq. They have proven that the (coalition's) strategy is working".

IS has lost much of the territory it controlled in the two countries and thousands of its fighters have been killed since late 2014, when the coalition was set up to defeat the group.

But the jihadist group, which is also known as ISIS, continues to claim attacks in the Middle East and Europe.

In a statement, the coalition against IS congratulated Mr Abadi and the Iraqi security forces "on their stunning victory in Tal Afar" and Nineveh province.

But it cautioned that "dangerous work remains to completely remove explosive devices, identify ISIS fighters in hiding and eliminate any remaining ISIS holdouts so they do not threaten the security of Tal Afar in the future".

Mr Croft said Iraqi forces had killed between 600 and 700 IS fighters during the battle for Tal Afar while around 100 more had surrendered.

IS fighters in Iraq now control only the town of Hawija around 300km north of Baghdad, as well as several areas in the vast western desert province of Anbar along the border with Syria.