Tens of thousands of protesters have taken part in what organisers say could be Hong Kong’s largest pro-democracy rally in more than a decade.

The annual rally, marking the day Hong Kong was returned to China in 1997, was to demand full electoral freedom.

It came after an unofficial referendum on how to choose Hong Kong’s next chief executive drew close to 800,000 votes.

China says it will introduce universal suffrage for the 2017 election – but wants the final say over who can run.

The Hong Kong government said the 10-day referendum had no legal standing.