![A general view of the o2 Arena as Switzerland's Roger Federer competes against Great Britain's Andy Murray during the Barclay's ATP World Tennis Tour Finals at the O2 Arena, London Stock Photo - A general view of the o2 Arena as Switzerland's Roger Federer competes against Great Britain's Andy Murray during the Barclay's ATP World Tennis Tour Finals at the O2 Arena, London Stock Photo -](https://c8.alamy.com/comp/GC6D68/a-general-view-of-the-o2-arena-as-switzerlands-roger-federer-competes-GC6D68.jpg)
A general view of the o2 Arena as Switzerland's Roger Federer competes against Great Britain's Andy Murray during the Barclay's ATP World Tennis Tour Finals at the O2 Arena, London Stock Photo -
![Security stepped up at ATP World Tour Finals after Paris terror attacks | ATP World Tour Finals | The Guardian Security stepped up at ATP World Tour Finals after Paris terror attacks | ATP World Tour Finals | The Guardian](https://i.guim.co.uk/img/media/da992301b66a8c8836ecef68e56991249b1872a6/0_271_5028_3017/master/5028.jpg?width=1200&quality=85&auto=format&fit=max&s=909c96599c34f440a4a9af2f106428b7)
Security stepped up at ATP World Tour Finals after Paris terror attacks | ATP World Tour Finals | The Guardian
![O2, London, UK. 16th November 2019. Visitors arrive in the O2 arena for semi-finals day at the 2019 Nitto ATP Finals as centre court prepares for the afternoon session of doubles and O2, London, UK. 16th November 2019. Visitors arrive in the O2 arena for semi-finals day at the 2019 Nitto ATP Finals as centre court prepares for the afternoon session of doubles and](https://c8.alamy.com/comp/2A9K3CJ/o2-london-uk-16th-november-2019-visitors-arrive-in-the-o2-arena-for-semi-finals-day-at-the-2019-nitto-atp-finals-as-centre-court-prepares-for-the-afternoon-session-of-doubles-and-singles-matches-credit-malcolm-parkalamy-live-news-2A9K3CJ.jpg)