Artists have been responding to the attacks. This is one of the most widely shared images, by @LucilleClerc, external:

Image source, Twitter/@LucilleClerc

Valerie from Lyon in France emails: I remember the Europa Hotel in Belfast which was bombed something like 25 times. Each time it was re-built. We have to do the same today.

Pope Francis tweets, external: "#PrayersForParis"

Maarten Jochems from Eindhoven in The Netherlands emails: Of course our first thought is: yet again we get confirmation of this retarded religion called Islam. But it is wrong to think so. There are extremists in any part of the world acting on behalf religion, superstition or blind ignorance. I embrace the actions of our Australian friends, who reached out to all their fellow citizens with Muslim backgrounds. Let's walk together and let's not have our beautiful lives and societies held hostage by retarded criminals. The only ones responsible for this heinous crime are the ignorant fools who pulled the trigger. Didn't know a cartoon could be this influential. Let's keep up the good work Charlie Hebdo! I'll subscribe even though my French is too limited to get all of your jokes!

Jonathan Sinclair emails: The best thing we can do is to carry on with our lives entirely unaltered, whilst of course respecting the families and loved ones of those so brutally murdered. We should not alter our attitude to the vast, vast majority of Muslims who are peace loving, but at the same time we cannot and should not in any way be intimidated into changing how we live our lives. Then the terrorists will have won.

A policewoman and a city employee are in critical condition after a man fired on them with an automatic rifle outside Paris, police say. No link has yet been established with Wednesday's deadly attack, AFP reports.

Interior Minister Bernard Cazeneuve has arrived at the scene of Thursday's shootings, AFP news agency reports.

Image source, AFP

French flags are tied with black ribbons at the Elysee Palace in Paris as the country observes a day of mourning.

Sabrina Kara emails: I am a proud Arab but never ever will be proud of such hypocrite, ignorant and filthy people. I hate these Muslims that spoil it for the good Muslims. There are so many out there who day by day have to suffer from actions like this. My thoughts and heart goes out to the families of the victims.

A day of mourning is getting under way in France for the victims of the attack. Flags are flying at half mast, including at the Elysee Palace, the president's official residence.

Image source, AFP

Phil Corrigan emails: Isn't it about time that all the leading "moderate" Muslim clerics throughout the world joined together in a united forum and led the way with a consistent and prolonged anti terror strategy in an attempt to clean up the cancer that has taken a firm stranglehold on their communities and Islam?

Mac emails: What the Charlie Hebdo killers want is for me to go out and stone a mosque, boycott Muslim businesses, spit on Muslims and in other ways help drive Muslims into the arms of the radicals. I will not acquiesce.

France's Interior Minister Bernard Cazeneuve left an emergency government meeting to travel to the scene of Thursday's shooting in which one officer was injured, AFP news agency reports. There is no known link with the Charlie Hebdo attack, police say.

French police have issued this call for witnesses as they hunt for Cherif and Said Kouachi, the two brothers suspected of the attack.

Image source, Reuters

Norman Smith
BBC Assistant Political Editor

Government sources say they think it unlikely the terrorism threat level will be raised in UK following the Charlie Hebdo terror attack. Sources say they do not believe there is any increased threat to the UK following the attack and so the level is expected to remain at "severe". However it's understood security is being stepped up at rail and ferry terminals - although sources say they have no reason to believe the gunmen may try to flee to the UK.

French President, Francois Hollande, convenes an emergency meeting of his cabinet about the attacks. In a speech on Wednesday, he said "the French Republic as a whole was the target".

Image source, AFP

Haran emails: We have to show the world what the true meaning of Islam is. Islam means Peace. Any attack on humanity doesn't justify its harm. But we also have to understand what freedom of speech really means. We can not use this freedom to ridicule any religion, if we all want to co-exist then we respect every religion.

Trevor Freeman in Hong Kong emails: Every single Western newspaper, magazine, TV and any other media HAS to publish these pictures that have offended extremists to shoot dead 12 people. It would show a solidarity that the western media will not be bowed and manipulated by such attacks. The publication of what they hate will just become far more widespread and where do they go from there? If we let this pass by, they are the winners and our media have been censored by murder.

An arrest has been made in the shooting which happened in south Paris this morning, AFP reports. There is no known link to the Charlie Hebdo attack.

Some of the rallies in support of Charlie Hebdo, in French Polynesia, the US and in Japan.

Image source, AFP

Image source, Reuters

Image source, AFP