PARIS (AFP) - The 40th edition of the Paris marathon will take place on high alert on Sunday following terrorist attacks on the French capital and Brussels, organisers said.
Paris suffered several attacks in 2015, with 17 people killed in the Charlie Hebdo satirical newspaper and a Jewish supermarket in January.
In November, another 130 people were killed and many injured in a series of attacks both in central Paris and on the outskirts at the Stade de France, where the Euro 2016 football final will be held on July 10.
A total of 32 people were also killed in the March 22 attacks on the airport and a metro station in Brussels.
But marathon organisers Amaury Sport Organisation (ASO) insisted there was never a question of cancelling the race as in 1991 because of France's military presence in the Gulf War.
"The question does not arise," said ASO director-general Yann Le Moenner.
Some 57,000 participants from 160 countries have registered with the race covering 42.195km, starting on the Champs Elysees and crossing the French capital to the Bois de Vincennes on the east.
Ten of thousands of spectators are also expected to line the route, with festivities planned particularly at the 40km mark, in honour of the first edition in 1976.
For the first time in race history the winners will bid to defend their titles - Ethiopian Meseret Mengistu, in the women's, and Kenyan Mark Korir the men's.
On average up to 10,000 runners who have registered fail to line up on the day and it remains to be seen if the Paris and Brussels attacks will have an impact.
But marathon director Edouard Cassignol insisted: "There is absolutely no psychosis.
"After the events of Nov 13, we received a lot of e-mails asking if the marathon was going ahead. Notably e-mails from Americans and foreigners. This phenomenon was not repeated after the dramatic events of recent weeks."
Race organisers declined to elaborate on the arrangements put in place for security reasons.
"We can't say much more, we have a commitment not to disclose the details of the plans because confidentiality ensures full efficiency," said Cassignol.
The Prefecture of Police in Paris said in a statement that "security measures will be reinforced by police teams at the start and finish zones in order to protect participants".
"They will carry out checks in support of an important filtering system set up by the organisers. There will be systematic pat downs of the public with bags checked. Similarly, patrols will be mobilised to secure the entire route taken by the runners.
"Emergency vehicles and assistance will also be on site as it is customary for this kind of event. Several hundred police officers will be mobilised for the occasion."
Marathon organisers insisted that security would be at a maximum with patrols and metal detectors used.
"The proposed system has been considerably strengthened," said Cassignol.
"We have strengthened baggage searches, both in terms of resources and materials, since staff will be equipped with metal detectors. We also plan spotters, people trained to detect any abnormal behaviour, and finally we briefed our nearly 3,000 volunteers on being vigilant on D-day," he said.