Thousands of people have gathered to celebrate Muhammad Ali's life at a traditional Islamic prayer service in the boxer's home town of Louisville, Kentucky.

Eastern Daily Press: The hearse with the body of Muhammad Ali arrives at Freedom Hall for an Islamic funeral prayer service Thursday, June 9, 2016, in Louisville, Ky. (AP Photo/Mark Humphrey)The hearse with the body of Muhammad Ali arrives at Freedom Hall for an Islamic funeral prayer service Thursday, June 9, 2016, in Louisville, Ky. (AP Photo/Mark Humphrey) (Image: Copyright 2016 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistribu)

Ali's former manager Don King and Reverend Jesse Jackson were among those arriving for the Jenazah at the Freedom Hall, where Ali made his professional debut with victory over Tunney Hunsaker in 1960.

Up to 18,000 people are expected at the event, with Ali fans travelling from around the world to honour the three-time world heavyweight champion.

Briton Abi Ajram, 48, said he had made the 4,000-mile trip from London to pay respect to 'a great man'.

He told the Press Association: 'I feel Muhammad Ali deserved the world turning up for him. I thought it's the least I can do and I wanted to do it the moment I heard he had passed away.

'He was the number one.

'I wanted to show my respect to a great man and an even greater humanitarian. He meant a lot to me.

'I met him at the Royal Albert Hall in 2000. I shook his hand. I didn't know what to say.'

Ali's funeral service is to be streamed live at London's O2 Arena, the site of his I Am The Greatest Exhibition.

It will be shown on the giant screens from 7pm BST by The O2's main entrance where the public can watch it, leave flowers, and also sign the book of condolence at the exhibition inside. It can also be streamed on AliCenter.org.

Ali, considered the world's greatest ever world heavyweight champion, died last Friday in Arizona at the age of 74 after being taken to hospital with a respiratory condition complicated by his long-term struggle with Parkinson's disease.

His funeral service is to take place in his hometown of Louisville, Kentucky, from 2pm ET. Tickets for that have sold out.