John Lennon's 'imagine' homage to Paris attack

Darkness looms over Paris as terrorist attacks have claimed the lives of many innocent civilians.

ISIS terrorist, posed as Serian refugees carried out coordinated attacks at six sites around Paris on Friday night, killing at least 129 people and wounding at least 352 others, prompting French President Francois Hollande to condemn the attack as an "act of war".

An an emergency national address, President Hollande declared three days of national mourning and raised France's security to its highest level. Hollande said ISIS was "a terrorist army ... a jihadist army, against France, against the values that we defend everywhere in the world, against what we are: A free country that means something to the whole planet."

Following the night's harrowing tragedy in Paris, the city's people are gathering in solidarity to pay respects and mourn the lives lost, and those injured.

A memorial scene near the Bataclan concert hall where one of the attacks occurred, a pianist set up a portable piano and played a cover of John Lennon's iconic song, "Imagine" for the grieving crowd.