The Islamic State group's empire has shrunk fast this year but the rump of its "caliphate" on the Iraq-Syria border is a hostile jihadist heartland where competing regional interests converge.

The desert towns of al-Qaim and Rawa near Syria's border in the Euphrates Valley, where Iraqi forces launched operations Thursday, constitute the final Islamic State group bastion in the country.

The battle between Spain's central government and the separatist leaders of Catalonia escalates day after day, forcing Catalan society to take a stand.

A century ago, on October 25, 1917, Lenin's Marxist Bolsheviks took control of Russia's imperial capital, launching the October Revolution that led to the creation of the Soviet Union.

The Islamic State group's former Syrian stronghold Raqa has been captured, but it lies ruined, littered with explosives, and lacking electricity or running water for residents desperate to return.

Aid groups and the United Nations say clearing and rebuilding what was once the jihadist group's de facto Syrian capital will be a massive, expensive effort, and it could be months before life resumes.

Catalonia's government has until 0800 GMT on Thursday to tell Madrid whether or not he is declaring independence from Spain.

The Islamic State group's defeat in Raqa, their de facto Syrian capital, raises a thorny question for the US forces that have been training and arming the victorious local fighters: What comes next?

Syria's war has spiraled into a complex multi-sided conflict since it began with anti-government protests in March 2011, drawing in regional and international powers including the United States and Russia. 

The Islamic State group seized swathes of Iraq and Syria in 2014, but its self-declared caliphate has now been crushed and it has lost its de facto Syrian capital Raqa. 

A U.S.-backed alliance of Kurdish and Arab fighters, the Syrian Democratic Forces, said it had fully captured the Islamic State group's former Syrian stronghold Raqa on Tuesday.