Hong Kong anti-government protesters crowded a shopping mall in running clashes with police on Sunday during which a man with a knife slashed several people and apparently bit off part of a local politician's ear.

A human chain in Cityplaza, in the eastern suburb of Taikoo Shing, turned into a face-to-face conflict with police, running up and down escalators where families with young children had been window shopping just minutes before and watching skating on the ice rink.

Police said protesters had vandalized a restaurant in the mall after a peaceful chanting of slogans in the 22nd straight weekend of protests by Hong Kong people furious at perceived Chinese meddling in the former British colony which returned to Chinese rule in 1997.

Several people were wounded, with one man in a white tee-shirt, believed to be the knifeman, being beaten with sticks by protesters. Another man lay in a pool of blood on the pavement outside the mall.

Democratic district councillor Andrew Chiu was among the wounded, blood dripping from his ear. Democratic Party lawmaker James To told reporters the knifeman had bitten off part of Chiu's ear and slashed other people.

He said the other wounded were in more serious condition than Chiu who was seen on TV holding the piece of his ear in a plastic bag with bloody hands.

A kitchen knife lay on the ground outside the mall.

Police made several arrests as protesters shouted "black police!", a reference to their perceived brutality. The standoff lasted into the night, with residents jeering police from the roadside and balconies of nearby apartments, chanting "leave now" and more colorful Cantonese expletives.

Police fired tear gas, outside the East Hotel in Taikoo Shing, to try to break up the crowds. They then left.

"These police are not what they used to be," said Julie, 24, giving police the middle finger. "They come in here and push us around. It is not right."