Jailed Hong Kong media tycoon Jimmy Lai was among eight democracy activists handed new prison sentences on Friday for attending protests on the 70th anniversary of the founding of communist China that were followed by a sweeping crackdown.

Mr Lai, who is already behind bars for taking part in earlier protests, must now serve a total of 20 months after pleading guilty to organising an unlawful assembly on 1 October, 2019.

Seven other leading activists, including 25-year-old youth campaigner Figo Chan, as well as former lawmakers Lee Cheuk-yan and Leung Kwok-hung, were also given new jail sentences.

The new sentences are the latest in a relentless and successful campaign by China to smother dissent and dismantle Hong Kong's democracy movement.