The costliest Olympic Games in history officially open in Russia on Friday, with 98 medals to be won over 16 days.

Sochi, on Russia's Black Sea coast, will welcome about 2,900 athletes in 15 disciplines as the opening ceremony begins at 20:14 local time (16:14 GMT).

The build-up has been overshadowed by security fears, human rights concerns and delays to preparations.

But, at £30bn, the cost of these Games is more than the combined total of all other Olympic Winter Games to date.

Canada, Norway and the United States are considered the likeliest candidates to top the Sochi medal table, while Team GB have been set a target of at least three medals in Sochi.

(Source: BBC)