While there are fears for the many priceless artworks and artefacts housed inside the cathedral, the rector of Notre-Dame, Patrick Jacquin, has told local press that the Crown of Thorns and the Tunic of St Louis have both been recovered.
- Copyright: AFPCopyright: AFP
French Deputy Interior Minister Laurent Nunez has announced that the fire has "decreased in intensity" and "the structure of the building is saved, including the north tower."Copyright: Getty Images
Radio France journalist Alexandre Fremont has tweeted an image captured by a drone flown above the cathedral, reportedly showing significant damage.
A French firefighting official has told Reuters that one fireman has been seriously injured tackling the blaze.
Footage posted on social media shows crowds of people singing as they witness Notre-Dame burning.
Reuters news agency is quoting an official with the French firefighting team as saying: "We can now say that the structure of Notre-Dame has been saved from total destruction".
AFP is also reporting that the main structure has been "saved and preserved", citing an official.
Finland's President Sauli Niinistö tweets: "Finland shares the sadness of this terrible fire at Notre-Dame cathedral. Our thoughts are with France and Parisians tonight."
Several churches around the French capital are ringing their bells in response to the blaze at Notre-Dame.
French fire chief Jean-Claude Gallet has told reporters he is not sure if the authorities will be able to stop the fire from spreading.
"If it collapses, you can imagine how important the damage will be," he added.Copyright: Getty Images
Henri Astier of BBC World Online writes about Notre-Dame cathedral and why no other site represents France quite like it.Copyright: Getty Images
Firefighters at the scene have told Reuters news agency that all efforts are now being directed at saving artwork in the cathedral and preventing the collapse of its northern tower.Copyright: Reuters
US-based firefighter Gregg Favre has put out this tweet thread discussing the adversity that fire crews in Paris are likely to be facing.
He explains why firefighters would need to enter the historical building in order to properly combat the fire, but may be unable to do so due to the risk of falling roofing timber.
He adds that the church, which is designed to be "open and airy" for Sunday worship has no shortage of oxygen which would fuel the fire.
French deputy interior minister Laurent Nunez has told reporters it is 'not certain' that the cathedral can be saved, according to news agency AFP.
The Vatican has said news of the fire has caused "shock and sadness," adding that it was praying for the French fire services.
Here are pictures of the famous Parisian church before and during the blaze.
The iconic 12th Century building is famed for its stained glass, flying buttresses and carved gargoyles.Copyright: AFPCopyright: Reuters
French fire chiefs have told news agency AFP they are not sure if the fire can be stopped.