An Iraqi army helicopter flies over the outskirts of western Mosul on April 6, 2017
Arbil (Iraq) (AFP) - The Islamic State group shot down an Iraqi helicopter operating over Mosul Thursday, as security forces announced they recaptured another neighbourhood in their nearly six-month-old offensive against the jihadist stronghold.
The operation to retake west Mosul -- which the helicopter was supporting when it was downed -- has become a slow, grinding battle that has taken a heavy toll on civilians and pushed more than 200,000 to flee.
"The helicopter was supporting federal police forces in (west Mosul) and was hit by fire and crashed in the Mohandiseen neighbourhood in east Mosul," Brigadier General Yahya Rasool, the spokesman for Iraq's Joint Operations Command, told AFP.
The city is divided by the Tigris River. East Mosul was recaptured earlier this year, but IS still holds significant ground on the city's western side.
Federal police are operating alongside interior ministry special forces in Mosul's Old City -- a densely populated warren of narrow streets and closely spaced buildings that is home to hundreds of thousands of people.
Rasool said the US-made Bell helicopter crashed about 3:00 pm (1200 GMT) on Thursday, and that he believed it was hit by 57 mm anti-aircraft fire.
Iraqi army aviation operates armed versions of the Bell 407 helicopter.
Strikes by Iraqi helicopters are especially important for the country's interior ministry forces, which have consistently complained of not receiving sufficient air support from the US-led anti-IS coalition during the Mosul operation.
The downing of the aircraft on Thursday comes after another helicopter crashed south of Mosul at the beginning of the year due to a "technical failure," killing four crew members.
- Neighbourhood retaken -
Rasool also said Thursday that Iraqi forces had recaptured a west Mosul neighbourhood called Yarmuk al-Thaniya.
Iraqi forces have retaken a series of neighbourhoods since launching the operation to recapture west Mosul in mid-February, though progress in the Old City area has been slow.
Civilian casualties in Mosul have come under increasing scrutiny in recent weeks, with the UN human rights office saying more than 300 were killed in the fighting.
The US-led coalition -- which has admitted that it "probably" played a role in recent civilian casualties in Mosul -- has said that the militants are surreptitiously forcing civilians into homes and then seeking to encourage air strikes on them.
IS has repeatedly targeted civilians with snipers, bombs and shelling in and around Mosul, and seized them for use as human shields.
The government has encouraged residents not to flee during the Mosul operation -- a policy aimed at easing ease the burden of widespread displacement but which can heighten the risk of injury or death for civilians.
The military announced on Wednesday that it had dropped hundreds of thousands of leaflets over IS-held areas of west Mosul and elsewhere urging civilians to shelter in their homes.
"Aerial bombing will target (IS) gangs and not civilians," the military said in a statement.
But irrespective of whether or not they are directly targeted, residents still can be, and have been, the victims of strikes aimed at IS fighters who are deployed in areas still populated by large numbers of civilians.
Iraqi forces backed by coalition air strikes have regained much of the territory they lost to IS in 2014, and launched the operation to retake Mosul in October.