British police have appealed to any UK nationals with pictures or footage relating to the Nice attack to come forward.
Scotland Yard has activated an online platform for uploading images and videos which could provide important information for investigating authorities.
More than 200 people were wounded and 84 killed after a 31-year-old French-Tunisian drove a truck through crowds celebrating Bastille Day in Nice.
The Met said: "The public and the media can help us by uploading any images or footage they may have taken at the scenes to www.ukpoliceimageappeal.co.uk."
Anyone with information that could assist the investigation should call the Anti-Terrorist Hotline on 0800 789 321, the force added.
Earlier, it emerged that forces around the UK will review security at major events scheduled to take place over the next week in the wake of the attack.