Struggle for Iraq: In mapsContinue reading the main story
The US has launched a series of air strikes in an attempt to halt the advance of Islamic militants in northern Iraq.
Strikes by F/A-18 aircraft have targeted mobile artillery which was being used to attack Kurdish forces defending Irbil - where US forces are based - and against militants attacking civilians near Sinjar.
Fighters from the Islamic State (IS), formerly known as Isis, have been steadily advancing eastwards. They seized Qaraqosh, Iraq's biggest Christian town last week.US strikes on IS militants
The latest IS advance has forced thousands from their homes in the north-west city of Sinjar, mainly to Dohuk and Nineveh governorates.
But at least 50,000 members of the Yazidi religious minority community are also trapped on nearby Mount Sinjar, where they sought refuge from the fighting.
A Kurdish official said the US air strikes on IS militants in Nineveh province had helped the Kurdish Peshmerga fighters retake the towns of Gwer and Makhmur after heavy fighting.Routes used by Sinjar refugees to escape violence
With the Yazidis facing starvation and dehydration on the mountain, as well as slaughter at the hands of IS militants if they tried to flee, US military aircraft have dropped tonnes of food and water aid onto Mount Sinjar.
British RAF aircraft also dropped fresh water containers and solar lanterns which can be used to recharge mobile phones.Continue reading the main story
The United Nations says it is working on opening a humanitarian corridor in northern Iraq to allow stranded people to flee.Mosul dam
IS is reported to have seized Iraq's largest hydroelectric dam at Mosul. The dam is of huge strategic significance in terms of water and power resources. The Tigris River south of the dam runs all the way to Baghdad.The rise of IS
The Islamic State has control of large swathes of Syria and Iraq. On 29 June, IS said it had created a caliphate, or Islamic state, stretching from Aleppo in Syria to the province of Diyala in Iraq.
Setting up a state governed under strict Islamic law has long been a goal of many jihadists.
Based on a details posted on Twitter earlier this year, the map below shows 16 "wilayats", or provinces, that Isis claims to control or where it claims to have a presence.
The areas where IS is operating largely match areas where its predecessor, al-Qaeda in Iraq (AQI), was active during the peak of the sectarian insurgency in 2006.
AQI was eventually suppressed through a combination of a surge in US troop numbers and Sunni tribesmen taking up arms to drive it out.
But earlier in June, IS militants overran Iraq's second largest city, Mosul - after taking the central city of Falluja and parts of nearby Ramadi in December 2013.IS presence in Iraq and Syria
Mosul - with its Sunni Arab majority - fell after the collapse of the Iraqi security forces. Although they far outnumbered the militant fighters, many police and soldiers just abandoned their posts and fled.Ethnic and religious divide
Iraq's Sunnis are increasingly disenchanted with what they see as their systematic marginalisation by the Shia-dominated government in Baghdad and targeting by security forces.Where the main jihadist groups based?
Jihadist groups are spread throughout Africa, the Middle East, and in parts of Asia. Some have connections to al-Qaeda, others do not. But they all share the common goal of creating an Islamist state through violence.
The situation on the ground is dynamic and the location and strength of these groups is constantly changing, as the IS (previously known as Isis) example shows. These groups often carry out activities outside of the areas shaded on the map below and there are many smaller groups or factions we have not shown, with similar aims.