Six people have been detained today in Brussels by police in relation to alleged planned attacks
Authorities in Paris have scaled back the city's New Year's Eve celebrations over heightened terror fears after Brussels cancelled its festivities.
The usual fireworks display in the French capital has been scrapped and replaced by a five-minute video performance at the Arc de Triomphe just before midnight, relayed on screens along the Champs Elysees.
About 11,000 soldiers, police and emergency workers are being deployed on the streets - 2,000 more than last year - seven weeks after 130 people were murdered in multiple attacks.
Around 600,000 people usually attend the annual events around the Eiffel Tower, Arc de Triomphe and Champs Elysees.
Paris mayor Anne Hidalgo emphasised that, although the fireworks had been cancelled, the festivities will go on.
"We have decided to mark the New Year in an atmosphere of sobriety and togetherness," she said.
"Tourists and residents alike will, as usual, be able to meet on what we know as the most beautiful avenue in the world, but this year, sobriety is here.
"There won't be a big show."
The French government said tens of thousands more troops will be on duty around the country.
"The same troops who used to be in Mali, Chad, French Guyana or the Central African Republic are now ensuring the protection of French people," said Defence Minister Jean-Yves Le Drian.
Brussels mayor Yvan Mayeur said the decision to cancel their display was made following a risk analysis by security experts.
Around 50,000 people were expected to attend the annual fireworks display in Place de Brouckere.
The only event that will continue is the Christmas markets.
Meanwhile six people have been detained today in the city by police in relation to alleged planned attacks.
The arrests were made this morning as officers searched several homes in the city.
Yesterday a 22-year-old suspect was detained during a search of a house in Brussels and later charged with terrorist murder and participation in a terrorist organisation, prosecutors said.
Another two men were held in Belgium on Sunday and Monday on suspicion of plotting militant attacks in the capital on New Year's Eve.
They were held during an anti-terrorist operation across Brussels and the neighbouring Brabant region as well as in the Liege area.
Brussels last called off its New Year fireworks display in 2007 after a plan was foiled to free Nizar Trabelsi, a former Tunisian footballer convicted of plotting to blow up a military base.
Belgium, and Brussels in particular, has been at the centre of investigations into the Paris attacks after it emerged that two of the suicide bombers who attacked the French capital had lived in the country.