In Iraq's western desert near the Syrian border, in a landscape of sand and rock, a signpost announces that you are entering al Qaeda's Islamic State of Iraq and the Levant (ISIL).
A short video of the sign was broadcast on jihadi websites last month and reflects a long-held goal of al Qaeda fighters to establish an Islamic emirate.
ISIL insurgents have increased attacks on strategic targets in parts of western Iraq in the past three months in a bid to make their putative state a reality, security officials and analysts say.
"Al Qaeda believes these areas do not have strong security and social ties to the central government so it would be easy to separate them from Iraq," independent analyst Hashim al-Habobi said. "This is the goal of all these attacks."
Al Qaeda fighters seized control of most of Iraq's Sunni Muslim areas after the 2003 U.S. invasion. American troops and local allies finally beat them back in heavy fighting during the "surge" of 2006-07, but today the fighters once again aim to control towns and cities and realise their dream of a state ruled according to strict medieval Sunni Islamic practice.
After years of plotting underground and on the Internet, they have joined forces with powerful groups fighting in neighbouring Syria against President Bashar al-Assad, and aim to establish a Caliphate that would transcend modern state borders.
"They want to establish their own state on the ground. It is not enough to have a state in the virtual world anymore," said a senior federal police officer who has attended interrogations of al Qaeda detainees in Baghdad.
He said that late last month the army uncovered an ISIL plot to seize border towns near Syria in western Anbar province and Anbar's main cities of Ramadi and Falluja. The plan was thwarted by a raid on a camp in Anbar's desert just two days before it was to have taken place, he added.
Fighters had planned to attack police stations, an army operations centre for four provinces in western and northern Iraq as well as government buildings in Ramadi and western towns, the officer said.
The attack would have involved suicide bombers on foot and in vehicles as well as rockets, like an attack in July that freed hundreds of prisoners from Abu Ghraib jail, the boldest insurgent operation in Iraq in more than five years.
Habobi, the analyst, said ISIL views Anbar and nearby Mosul city as the core of a wider area that could be wrested from control of the Shi'ite-led Baghdad government and serve as a haven to move freely in and out of Syria.
The rise of ISIL and its allies in neighbouring Syria has already transformed that conflict and forced a rethink among Western countries backing rebels against Assad.
The United States and Britain suspended assistance into northern Syria on Wednesday after Islamists seized headquarters and warehouses there from Western-backed rebels.
ISIL, which announced its formation earlier this year out of pre-existing groups, operates on both sides of the frontier, though it is not clear how closely Syrian and Iraqi wings coordinate their activities.
In Iraq it has claimed responsibility for mass bombing campaigns that have killed thousands of civilians this year, by far Iraq's worst violence since the U.S. surge.
In Syria, ISIL is led by foreigners hardened by guerrilla warfare in Iraq, Chechnya and Libya and has seized expanses of land in rebel-held areas. In some places it has tried to implement a rigid Islamist social agenda.
Iraq's Foreign Minister Hoshyar Zebari has estimated the total number of ISIL fighters at 12,000, a figure that appeared to cover both Syria and Iraq.
"This is toxic, and the day will come, God forbid, when they will have another Islamic Emirate outside control," he told a security conference in Bahrain this week.
VIRTUAL STATE NOT ENOUGH
In Iraq the group is mainly based in the natural valleys and caves in western and northern parts of the country's vast desert, which is an expansion of the Syrian desert.
Since September, ISIL has bombed four bridges on routes linking the Iraqi border towns of Rawaa, Aana, Haditha and Rutba to the Anbar capital Ramadi, 100 km (60 miles) west of Baghdad.
This was to stop security services from sending back-up forces when ISIL attacked security headquarters and troops in the border towns, security officials said.
The Western Sunni province of Anbar occupies a third of Iraq's territory and borders Syria, Saudi Arabia and Jordan.
Its cities and towns, strung along the vast stretch of the Euphrates river as it spills out of Syria, are populated by Sunni Muslims, many of whom resent the dominance of Shi'ites in the government in Baghdad.
Thousands took to the streets in anti-government protests late last year, and there have been smaller gatherings since.
When al Qaeda fighters last controlled Anbar before the U.S. surge, much of the population turned against them because of their harsh methods of justice and disregard for local tribal leaders. But there are signs they are again gaining support.
A video posted on jihadi websites earlier this month shows dozens of masked ISIL members holding machine guns in a military-style parade in a residential area near the highway in Anbar. There is a small group of observers cheering and waving.
The parade took place in late November near a square in the city of Ramadi where protesters regularly gather, witnesses and security officials in Anbar told Reuters by telephone. The crowd welcomed the masked men, they said.
Anbar authorities have installed curfews several times in the past two months because of intelligence reports warning of possible attacks on government buildings and troops.
"The intelligence we have been getting shows that the militants are seeking to control the province again," said Falih al-Essawi, deputy head of Anbar's provincial council.
In late October, in what appeared to be a coordinated assault, suicide bombers and other attackers targeted security headquarters and checkpoints in Anbar, killing at least 16 members of the security forces and wounding 35.
Two days earlier, bombers driving cars packed with explosives attacked sites in the border town of Rawa.
ISIL claimed responsibility for both assaults.
NORTH AND SOUTH JAZEERA
The group has set up two desert areas that it refers to as "wilayah", a type of governed area; one is called the State of North al-Jazeera, outside the northern city of Mosul, and the other the State of South al-Jazeera, in the Anbar desert.
The areas include camps, training centres, command headquarters and stocks of weapons, security officials say.
ISIL fighters control villages, oases, grazing areas and valleys in these areas, while the Iraqi army is based in military barracks scattered across the desert, security officials and residents said.
"Establishing a geographical area comprising natural resources such as oil and gas and totally dominated by Sunnis is a priority for the ISIL in this stage," said a retired senior military officer who was responsible for making plans to combat al Qaeda.