HONG KONG (AP) — A sea of protesters is marching through central Hong Kong in a major demonstration against government-sponsored legislation that would allow people to be extradited to mainland China to face charges.

The massive protest Sunday is taking place three days before Hong Kong's government plans to bring the bill to the full legislature in a bid to win approval by the end of the month.

The legislation has come under widespread criticism from human rights and business groups. Opponents say that China's legal system would not guarantee the same rights to defendants as in semi-autonomous Hong Kong.

The former British colony was returned to China in 1997 but retained the right to its own social, legal and political systems for 50 years under a "one country, two systems" framework.