U.S. Republicans have taken to social media in droves to burn their voter registration cards, renounce their political affiliation, and pledge never to vote for their party's presumptive nominee Donald Trump in November.

Trump is basking in the glory of an all-but-certain victory in the chaotic GOP nomination race, after rivals Ted Cruz and John Kasich raised their white flags of surrender.

After over one-and-a-half years of cohabitation, cracks are emerging in Turkey's ruling tandem of President Recep Tayyip Erdogan and Prime Minister Ahmet Davutoglu, sparking uncertainty over the premier's future.

Many believed Davutoglu would be a puppet premier when Erdogan switched to the presidency in August 2014, but the former foreign minister has made conspicuous efforts to carve out his own profile, to the possible irritation of the combative head of state.

Economic concerns and the desire for a sense of purpose and revenge are the major factors pushing young Syrians into the arms of jihadist groups, a study released on Wednesday found.

The report by peace activist group International Alert draws on interviews with 311 Syrians, their families and members of their communities in Syria, Lebanon and Turkey.

With U.S. and European support, African states threatened by Boko Haram are out to smash the militant Islamist group terrorizing the region -- but a coordinated response is required if they are to succeed.

A regional offensive launched early last year against the group by Chad, and Nigeria under new President Muhammadu Buhari has seen Boko Haram driven out from numerous towns and villages that it controlled in northeastern Nigeria.

Five years after the killing of Al-Qaida chief Osama bin Laden, the network he founded is far from dead even if it has suffered a series of setbacks.

Replaced as the preeminent global jihadist power by the Islamic State group, Al-Qaida nonetheless remains a potent force and dangerous threat, experts say.

Germany will Tuesday start its first war crimes trial over atrocities in Syria, as a mass refugee influx brings not only witnesses and victims but also suspects into the country.

Aria L., a 21-year-old German national and suspected jihadist, posted on Facebook photos of himself posing next to two decapitated heads in Syria -- and his case is not the only one from the war-torn country to occupy German justice.

Salah Abdeslam is sitting on a potential goldmine of information as the last surviving member of the Paris attacks terror squad.

The 26-year-old, accused of playing a key logistical role in the attacks, has promised to "explain himself" to French investigators, but it remains to be seen how much he will reveal.

As world powers backing peace talks continue to insist Syria's ceasefire is holding, residents of battered second city Aleppo can only express stunned disbelief.

"I don't know what truce they're talking about. There's no truce here," Abu Mohammed, a father-of-four living in the rebel-held east of the city, told AFP.

Saudi authorities will have to confront a range of vested interests if they hope to pull off an ambitious plan to diversify the economy away from oil, analysts said.

The "Vision 2030" plan, unveiled Monday by the kingdom's powerful Deputy Crown Prince Mohammed bin Salman, aims to transform an economy that has for decades relied mainly on Saudi Arabia's vast oil resources.

President Barack Obama's challenge that Europe unite and shoulder more of the burden for its own security might soon be answered, in part, by a military mission off the Libyan coast.

"Europe has sometimes been complacent about its own defense."