Iraq army seizes key airbase south of Mosul from Islamic State

Iraqi forces have captured a key airbase from the Islamic State (IS) group that can serve as a launchpad for retaking the militant-held city of Mosul, Prime Minister Haider al-Abadi said on Saturday.

The Qayyarah airbase in the Tigris valley 60 kilometres south of Mosul would be "an important base for the liberation of Mosul," Abadi said in a statement.

He called for the people of Iraq's northwestern Nineveh province, of which Mosul is the capital, to "prepare for the liberation of their cities."

Iraq's Joint Operations Command said two army divisions and members of the country's counter-terrorism forces took the base with air support from a US-led international coalition.

At least 38 militants were killed in the operation, Sabah Nouri, spokesman for Iraq's counter-terrorism unit, said on Saturday over Iraqi state television.

The forces also destroyed four trucks mounted with machine guns and detonated more than 100 improvised explosive devices, Nouri said.

Security sources said militants had fled towards Mosul after the base was taken.

An officer taking part in the operation said bomb disposal teams were removing booby traps and mines left behind by IS fighters.

No further details were immediately available on the scale of fighting for the base.

At the end of last month, Iraqi forces recaptured Fallujah, a city 50km west of Baghdad, in a major setback for IS.

That focused attention on the battle to remove IS from the northwest of the country.

In recent months, IS has lost significant parts of the territory north and west of Baghdad that it seized in 2014.

The fighting to get into Fallujah was initially fierce, particularly on the southern side, and Iraqi forces were supported by more than 100 US-led coalition air strikes.

On June 26, Abadi stood outside a hospital in Fallujah and vowed that the Iraqi flag would soon be raised over Mosul.

In his statement on Saturday, he said government forces had advanced 100km in the past few days.

"This is important revenge against the terrorist gangs, which we will crush and cleanse from all of our land very soon," he said.

Rights groups have raised concerns about alleged abuses carried out by Iraqi forces during the fight for Fallujah, including executions of civilians.

Human Rights Watch called on the government on Thursday to be transparent about an enquiry into the alleged abuses, which it said was "mired in secrecy". 

More than 80,000 people have been displaced since the start of the Fallujah offensive, bringing to more than 3.3 million the number of Iraqis forced from their homes by conflict since the start of 2014.

The Sunni extremist group has responded to its battlefield setbacks by hitting back against civilians, particularly Shias.

Experts have warned there may be more bombings as the militants continue to lose ground.

IS said it had carried out an attack on a Shia shrine north of Baghdad that started Thursday evening and killed 30 people.

That came just days after a devastating bombing in the capital that killed 292 people.