Iraq's newly-elected parliament convened Tuesday to begin choosing a government, with premier Nuri al-Maliki's bid for a third term battered by a Sunni militant offensive threatening to tear Iraq apart.

World leaders and senior clerics have urged Iraq's fractious politicians to unite in the face of the militant onslaught, which has killed more than 2,000 people, displaced hundreds of thousands and polarised the country's Shiite, Sunni and Kurdish populations.

Iraq has appealed for US air strikes in the face of the offensive and has purchased more than a dozen Russian warplanes to bolster its fledgling air force as it takes the fight to militants holding a string of towns and cities.

But Washington, which further bolstered security at its embassy on Monday, has so far not acceded, and has said that planned deliveries of F-16 fighter jets could even be delayed.

Iraq's Shiite premier has been criticised by his domestic opponents as being sectarian and for consolidating power, leading to resentment among the minority Sunni population and spawning the militant advance.

The offensive, which Iraq's security forces have struggled to hold back, has undermined Maliki's case for re-election after April's election initially left him in the driver's seat, analysts say.

"This has become a much more competitive race for the premiership position," said Ayham Kamel, Middle East and North Africa director for the Eurasia Group consultancy.

He echoed the expectation of several lawmakers who have told AFP that, despite pressure from Western countries and powerful religious leaders to urgently form a government when lawmakers began meeting on Tuesday, a new cabinet was unlikely to be in place for several weeks.

- 'More inclusive' -

"The broad direction here is to be more inclusive, at least when it comes to the Sunni community, and figure out a power-sharing deal," Kamel added.

Though the vast majority of Iraq's Sunni Arab minority do not actively support militants, analysts say their anger over alleged mistreatment by the Shiite-led authorities means they are less likely to cooperate with the security forces, fostering an environment in which militancy can flourish.

Kamel noted, however, that any military successes on the ground could boost Maliki's chances, with thousands of troops taking part in an ambitious operation aimed at retaking executed dictator Saddam Hussein's hometown of Tikrit, which fell on June 11.

Iraqi forces initially wilted in the face of the onslaught but have since performed more capably, with security officials touting apparent progress in recapturing the city.

A security source based near the city said reinforcements arrived with tanks and artillery Monday, with an army officer saying the Iraqi military controlled parts of the outskirts of Tikrit.

They have nevertheless suffered heavy casualties in recent weeks, with nearly 900 security personnel among the 2,400 people who died in June, the highest such figure in years, according to the UN mission in Iraq.

And though weeks earlier they managed to fend off a militant assault on Samarra, a predominantly-Sunni city that is home to a revered Shiite shrine whose destruction by Al-Qaeda in February 2006 ignited a full-blown confessional war, mortars landed near the shrine Monday evening, indicating the insurgents' proximity.

- Islamic 'caliphate' -

The security forces are battling militants led by the Islamic State (IS) jihadist group, which on Sunday declared a "caliphate", an Islamic form of government last seen under the Ottoman Empire, and ordered Muslims worldwide to pledge allegiance to their chief, in a bid to extend their authority.

In an audio recording distributed online, the group -- formerly the Islamic State of Iraq and the Levant -- declared its chief Abu Bakr al-Baghdadi "the caliph" and "leader for Muslims everywhere". Henceforth, the group said, he is to be known as "Caliph Ibrahim" -- a reference to his real name.

Though the move may not have immediate significant impact on the ground -- with Washington and other Syrian rebel groups dismissing its importance -- it is an indicator of the group's confidence and marks a move against Al-Qaeda, from which it broke away, in particular.

The group is known for its brutality, summarily executing its opponents and this week crucifying rival rebels in Syria.

US President Barack Obama deployed 200 additional troops to Baghdad to protect Washington's sprawling embassy here, as well as the airport, bringing the overall number of American soldiers and embassy security forces to 800.

The Iraq offensive has spurred international aid organisations to call for the establishment of humanitarian corridors to help those in need, with 1.2 million Iraqis having fled their homes as a result of unrest this year.

Football-crazed Iraqis watch World Cup despite danger
Baghdad (AFP) July 01, 2014 - Raad Abdulhussein sits glued to a television in a Baghdad cafe, anxious over the dual concerns of his team trailing in a World Cup match, and the danger of bombings.

He puffs continually on a waterpipe as he sits quietly with three friends in the "Facebook" cafe, the silence only broken by shouts or clapping when the Netherlands advance toward Mexico's goal.

"Football brings us together," says Raad, a 30-year-old taxi driver, who visits the cafe every day with his friends to watch the matches, which due to the time difference are broadcast in the evening in Iraq.

"It is our only way to leave the atmosphere of worry and tension and fear of the unknown," he says.

"A car may explode at any moment, or a bomb, or a person enters the cafe and blows himself up," Raad says.

This year's World Cup comes during an unprecedented decline in security within Iraq, with Sunni militants led by the Islamic State (IS) jihadist group overrunning parts of five provinces in a lightning offensive that Iraqi soldiers and police are struggling to contain.

While the militant drive has yet to truly threaten Baghdad, the group's spokesman has vowed its forces will push on to the Iraqi capital and Shiite shrine cities farther south.

But the offensive is by no means the first time Baghdad residents have faced threats while going out to watch matches -- the capital has lived under constant threat of bombings and violence for years.

Cafes are especially dangerous places, as militants often target them and other places where crowds of people gather, including markets and mosques.

Late last year, Baghdad security officials even held a seminar for cafe owners on how to deter and stop suicide bombers, after nearly 50 cafes were bombed nationwide in barely six months.

- Danger worsened in Ramadan -

That danger is compounded during the current holy Muslim fasting month of Ramadan, when militants sometimes carry out attacks following the meal known as iftar that breaks the daily fast.

But with the World Cup only held every four years, football-crazed Iraqis still take to cafes to watch matches, especially as many suffer lengthy power cuts that prevent them from tuning in at home.

"The atmosphere of the (World Cup) outside the home is better," says Osama Salem, a 31-year-old salesman.

But he adds with disappointment that "we have supported the Netherlands team for years, and the Netherlands are now down a goal."

"The World Cup is organised once every four years -- do we sit in our homes and give in to fear?" he continues, while trying to focus on the match, which the Netherlands ultimately won.

"We sit and we are afraid, but what can we do?"

"God willing, this ordeal will end," he says, fatalistically adding that if it is one's time to die, you will die wherever you are.

In sharply-divided Iraq, football is one of the few unifiers. This was especially the case in 2007, when the country cheered on the national side as it won the Asia Cup at the height of a brutal sectarian war in which tens of thousands were killed.

The World Cup "is the most beautiful thing. The whole world is watching it, and the people here are overjoyed by it and come to watch" until late at night, says Ali Hussein, a 21-year-old who works at the Facebook cafe, where patrons must go through strict security measures before they enter.

"Football is life for Iraqis, and we all remember the year 2007, when all the people went out in the street, no Sunni and no Shiite and no Kurds -- everyone behind the team."

"If Iraq qualified for the World Cup, maybe it would unite us again."