According to reports from multiple news sources, at least 35 people have been killed in Paris.
As well as shootings in a Paris restaurant and explosions near the country’s main sports stadium, up to 60 people are reportedly being held hostage at the Bataclan arts centre.
Paris authorities have asked people to stay indoors, as military personnel are deployed across the city.
Prime Minister David Cameron has said that he is "shocked" by the atrocities, adding: "We will do whatever we can to help."
Labour leader Jeremy Corbyn called the attacks "heinous and immoral".
Meanwhile President Barack Obama has said that the USA is prepared to provide whatever assistance France needs.
He told reporters: “We’ve seen an outrageous attempt to terrorise innocent civilians.
“This is an attack not just on Paris, an attack not just on the people of France, but this is an attack on all of humanity and the universal values we share.”
Our thoughts are with the victims and their loved ones at this time.
We will bring you more on this story as it develops.
UPDATE:
At least 120 people have been killed, and a further 200 people left injured (80 seriously) in the shocking coordinated gun and bomb attacks on Paris.
8 attackers are also reported to have been killed, 7 of whom died detonating suicide belts.
Attack sites include the State De France (the city's football stadium),
Le Carillon bar, Le Petit Cambodge restaurant, La Belle Equipe, La Casa Nostra restaurant, and Bataclan Hall, a concert venue which seats 1,500 people.
The attack on Bataclan was by far the deadliest; gunmen burst in and opened fire on concert-goers watching US rock group Eagles of Death Metal. The event had been sold out.
It is understood that the four gunmen took twenty hostages, and that when security stormed the building, three of them killed themselves by detonating their suicide belts.
The fourth was shot dead by police.
No terror group has claimed responsibility for the attacks.
However, during a televised address amid the attacks, the French President, without naming any group, said: "We know where these attacks come from. There are indeed good reasons to be afraid."
President Hollande went on to declare a national state of emergency in Paris.
“As I speak, terrorist attacks of an unprecedented scale are taking place in the Paris region,” he said in a nationally televised address. “There are several dozen dead, lots more wounded. It’s horrific.”
All citizens have been asked to stay inside their homes as military and police forces are deployed across the city.
We will bring you more on this story as news unfolds.