Fury in Hong Kong after activist beaten by police

Harrowing images of police officers apparently beating up a democracy activist after he was led away in hand restraints escalated tensions in Hong Kong, as the territory's richest tycoon called for an end to protests.

After days in which the protests appeared to be losing direction and barricades were falling, outrage over the beating of Ken Tsang, a member of the pro-democracy Civic Party, galvanised support for the Occupy Central movement and other student protest groups.

"This appears to be a vicious attack against a detained man who posed no threat to the police," said Mabel Au, director of Amnesty International Hong Kong. "Any investigation into this incident must be carried out promptly and all individuals involved in unlawful acts must be prosecuted."

Hong Kongers are protesting against restrictions imposed by Beijing on how it chooses its next leader in 2017, and they also are calling for the territory’s pro-Beijing leader, Leung Chun-ying, to step down.

In recent days, the numbers occupying Central had dwindled from about 100,000 at their peak to a few hundred, but official inaction by the government drove many back on to the streets, blockading a key underpass. The police response was the most hardline since demonstrators were doused in tear gas and sprayed with pepper spray last month.

Police officers dragged away dozens of protesters, tore down barricades and removed concrete slabs the protesters were using as road blocks around the territory’s central business district.

Hong Kong TV ran footage of the police allegedly beating up Mr Tsang, which went viral. Subsequently, the police said that officers involved in the incident would be removed from their positions, sparking further outrage.

Hong Kong secretary for security Lai Tung-kwok told a news conference that police would investigate the suspected use of excessive force. There were also accusations that Mr Tsang was beaten in the police station later.

Meanwhile, China appeared to entrench its position on the territory that reverted to rule by Beijing in 1997. A Chinese official blamed "foreign forces" interfering in the protests from outside forces and called on international journalists to report "objectively". The central government said the protests were "illegal, bad for business and against Hong Kong's best interests".

Hong Kong's most prominent tycoon, Li Ka-shing, urged protesters who have occupied parts of the city since late last month to go home. Mr Li is Asia's richest man and chairman of property developer Cheung Kong. He had made no public comment so far but said that an end to Hong Kong's rule of law would be the city's "greatest sorrow".