France strikes IS;global resolve against jihadists intensifies

French warplanes pounded Islamic State targets and Russia vowed to ramp up its bombing campaign in Syria today as the devastating attacks on Paris galvanised international resolve to destroy the jihadists and end the Syrian war.

In a grieving Paris, US Secretary of State John Kerry said a "big transition" in Syria was probably only weeks away as he expressed solidarity with the French nation after IS gunmen and suicide bombers massacred 129 people in the capital on Friday night.

Kerry said an agreement between deeply divided countries such as Iran, Russia and Saudi Arabia on a path to elections in Syria at talks held in Vienna Saturday was a "gigantic step", and he expected rapid progress.

"We are weeks away conceivably from the possibility of a big transition for Syria," he said.

The quickening political process came as French President Francois Hollande vowed to pursue IS mercilessly for their "acts of war" and Russia sought vengeance after finally confirming it believed a bomb attack did bring down a Russian passenger jet over Egypt last month that killed 224 people.

The IS group which operates out of Iraq and Syria claimed responsibility for downing the airliner as well as a bombing in Beirut last week.

"My sense is that everybody understands that... we have to step up our efforts to hit them (IS) at the core where they're planning these things," said Kerry.

"We've agreed to exchange more information, and I'm convinced that over the course of the next weeks, Daesh will feel even greater pressure," he added, using another term for IS.

Hollande will visit Washington next week to meet President Barack Obama, and is also planning a meeting with Russian President Vladimir Putin in the coming days.

And as the probe into the horror intensified, French police carried out more than 100 raids for a second night running, as a manhunt continued for 26-year-old Salah Abdeslam, one of two Belgium-based brothers implicated.

In Paris, stunned residents continued to flock to shrines of candles and flowers, while photographs of smiling young victims have been pasted at attack sites or outside their places of work.

The city is palpably more shaken than after the January attacks which killed 17 people at Charlie Hebdo magazine and a Jewish supermarket, but many have defiantly returned to sidewalk terrace cafes where they can be heard poring over the details of the assault.

But a shadow still hangs over the City of Light four days after IS suicide bombers and gunmen struck as Parisians watched a France-Germany football match, a concert by Californian group Eagles of Death Metal, or enjoyed a night out at restaurants and sidewalk cafes.