More than 140 people are feared to have been killed in a series of attacks during a night of terror in Paris, in the worst violence to hit France since the Second World War.
President Francois Hollande declared a state of emergency and re-imposed border control checks after two suicide attacks and a bombing near the Stade de France stadium, shootings at restaurants and a massacre inside a popular music venue.
It is not clear how many attackers were involved in what President Hollande described as an "abomination", but all are thought to be dead, the city's police chief said.
The authorities are continuing the search for any possible accomplices in the attacks.
In horrific scenes officers stormed the Bataclan concert hall where hostages were being held but attackers, wearing suicide belts, blew themselves up, leaving at least 100 people dead.
One official described "carnage" inside the building, saying the attackers had tossed explosives at the hostages.
President Hollande visited the scene in the early hours and said the country will be "merciless" against those who have attacked them.
"We will lead the fight. We will be merciless," he said.
World leaders including Barack Obama and David Cameron have spoken of their shock and outrage at the violence.
The Prince of Wales is to send Mr Hollande a message of "profound sympathy and solidarity with the people of Paris", a Clarence House spokeswoman said.
Charles and Camilla are currently on a tour of Australia, and will continue with engagements in Albany and Perth today, the spokeswoman added.
It is understood the prince, who is 67 today, will begin a planned celebration barbecue event by asking his guests to join him in expressing their sympathy with the French people.