Memorial services have been held around the world for the victims of the 9/11 attacks.
Nearly 3,000 people were killed when Muslim extremists hijacked four planes and flew two into the World Trade Centre and a third into the Pentagon on September 11, 2001.
Memorial services were taking place at the crash sites, with a remembrance event at Ground Zero in Manhattan followed by rallies for and against plans to open an Islamic centre nearby.
Speaking at the Pentagon, US President Barack Obama said the anniversary should be a day not only to mourn the 9/11 victims but to show that Americans "are not at war against Islam".
He added: "We're at war against terrorist organisations that have distorted Islam or falsely used the banner of Islam to engage in their destructive acts."
British victims of the atrocity were remembered in Grosvenor Square, London, as floral tributes were laid on behalf of the UK and US governments. A senior Civil Service official placed 67 roses - one for each of the British victims of the September 11 attacks.
The flowers carried a hand-written message from Prime Minister David Cameron, which read: "In memory of the victims of terrorism in the USA on 11 September 2001. They will never be forgotten."