Battle for Mosul: The story so far
Tens of thousands of civilians are fleeing the northern Iraqi city of Mosul as government security forces continue their military offensive to reclaim the city from the so-called Islamic State (IS).
After taking the airport, Iraqi forces have made key gains in the west of the city, recapturing several bridges, as well as government buildings.
They are closing in on the densely-populated old city of Mosul, and the Great Mosque of al-Nuri, where IS leader Abu Bakr al-Baghdadi proclaimed the creation of a "caliphate" in July 2014.
Iraqi security forces, Kurdish Peshmerga fighters, Sunni Arab tribesmen and Shia militiamen, assisted by US-led coalition warplanes and military advisers, are involved in the operation, launched on 17 October 2016.
IS jihadists overran Mosul as they spread across much of northern and western Iraq two years earlier in 2014.
Government forces announced the full "liberation" of eastern Mosul in January 2017. But the west of the city presents a more difficult challenge, with its narrow, winding streets. IS has launched multiple suicide attacks against Iraqi forces in western neighbourhoods.
Territorial control: Since 20 February 2017
More than 180,000 civilians have fled the city since the latest assault on west Mosul began on 19 February, according to the Iraqi government. Most have taken refuge in nearby camps and reception centres. Others have gone to stay with relatives and friends.
There is also deep concern for the hundreds of thousands of people who remain in western Mosul. Food supplies are running very low, and some families say they cannot find any food at all. Clean drinking water is also in very short supply.
The UN said in late January that almost half of all the casualties in Mosul were civilians. At least 1,494 have been killed and 1,219 injured across Nineveh province since the start of October.
Lt Gen Stephen Townsend, the coalition's task force commander, described the recapture of eastern Mosul as a "monumental achievement" for the Iraqi people, but warned there was "still a long way to go" before IS was eliminated from Iraq.
It took from mid-October until 8 January 2017 for Iraqi forces to advance as far as the River Tigris and another two weeks to gain full control of the eastern side of Mosul.
- Iraq forces seize Mosul airport from IS
- Iraq gaining momentum against IS
- Battle for western Mosul will be toughest yet
- Crisis in maps
Elsewhere in the region, the Shia-dominated, paramilitary Popular Mobilisation force has been advancing westwards towards the town of Tal Afar, another IS bastion, and the border with Syria.
Contradictory reports mean it is difficult to know exactly how much territory has been regained.
The maps shown here are based on expert analysis from two different sources, the Institute for the Study of War (for the recent advances) and IHS Conflict Monitor for territory.
According to analysis by IHS Conflict Monitor, IS fighters have been losing territory since the offensive began. However, gains slowed when Iraqi government forces met stiff resistance in the city of Mosul.
Satellite images have revealed extensive damage to Mosul's infrastructure, buildings and archaeological sites - in particular to the city's airport and bridges.
Imagery, released by US geopolitical intelligence company Stratfor in October 2016, showed how IS fighters sabotaged much of the city's airport, with wide trenches carved into it and rubble placed along their lengths.
The images also show how coalition airstrikes, aimed at destroying key IS positions and assets, caused damage to Mosul's sugar factory - a facility kept in action by the militants.
Imagery also revealed how the jihadists constructed multiple barricades across key routes into the city, including north of the airport.
The barriers have been made out of concrete blocks and other rubble, Stratfor's analysis says, possibly from the walls of destroyed buildings.
All bridges linking the east and west of the city, across the Tigris river, were also destroyed.
In the centre of the city, four of the five main bridges were put out of action in October and November by coalition air strikes, with the aim of limiting the jihadists' ability to resupply or reinforce their positions in the east.
The Old Bridge - the only remaining route open to vehicles in the centre of the city - was disabled in a US-led coalition air strike at the end of December.
Iraqi forces have since recaptured two of the bridges, the Fourth bridge and al-Hurriya, also known as the al-Jamhuriya. They will either have to repair them or install floating bridges to reconnect east and west Mosul.
Stratfor images show how the bridges were damaged.
A US air strike damaged the al-Hurriya Bridge at the eastern end last October, but IS then set up a barrier on the western side, shown below.
In November 2016, a US air strike damaged the bridge, but more recently it was rendered impassable by further damage, shown below.
The UN has warned that the offensive to retake western Mosul could displace up to 400,000 civilians and involve a siege in the densely-populated old city.
More than 355,000 people have fled their homes in and around Mosul as a result of the conflict - more than 180,000 of them have fled since the campaign began to retake the west of the city on 19 February.
More than 195,000 displaced Iraqis are now living in the 21 camps built by the UN and other agencies around Mosul. More camps are planned to cope with the sudden spike in refugees caused by the offensive against western Mosul.
The organisation says many of those who have fled Mosul and ended up in the camps have witnessed the deaths of relatives, friends and neighbours. Children are showing severe signs of trauma - such as excessive crying, mutism, bed-wetting and fear of leaving their parents.