Residents of a Chinese village once seen as a cradle of grassroots democracy are in shock after a "wild crackdown" by police in clashes with protesters which they said led to about 70 people being detained.

Hong Kong rights activists fear yesterday's violence marks a last-ditch push to silence Wukan, a southern fishing village in Guangdong province, which received international attention when a 2011 uprising over land grabs forced authorities to back down and grant local direct elections.

"Most people have been scared badly," said a villager named Chen.

"This time it was a wild crackdown. They went after everyone, chasing them up into their houses, beating people."

As she spoke, peeking nervously from behind curtains in her home, scores of riot and security police tightened a cordon around Wukan.

Violence flared in the 10,000-strong hamlet early on Tuesday as police launched pre-dawn raids on homes seeking leaders of protests that had rumbled since June after the arrest of a popular leader.

Village chief Lin Zuluan, one of the last of the 2011 protest leaders to remain in office, was jailed this month for three years on graft and other charges.

Villagers threw bricks at police as they advanced with shields, batons and helmets, firing rubber bullets and using tear gas. Some residents suffered wounds to their legs, mobile phone footage seen by Reuters showed.

Many said the violence was worse than that in 2011, when the village was locked down for several months.

Repeated calls to the Guangdong provincial government for comment went unanswered.

Tension rose again as dusk fell on Wednesday, with uniformed and plain-clothed police starting more house-to-house searches, seeking both protest organisers and journalists, villagers reported.

The sound of police speaking through loud hailers echoed through the streets. It was not clear what they were saying.

WRISTS BOUND

While low-level democratic experiments have been tried in villages across China, Wukan's took place in the glare of both domestic and international publicity - and marked a rare moment when Communist Party officials backed down in the face of protest.

Beijing leaders are fearful of growing calls for democracy and losing their grip on power. Weeks of "umbrella revolution" pro-democracy protests in Hong Kong, to the south-west of Wukan, in 2014 presented Beijing with one of its biggest political challenges in decades.

Protestors are angry at the jailing of Wukan village chief Lin Zuluan (pictured on poster). Photo: Reuters/Bobby Yip

According to the mobile phone footage seen by Reuters, elderly villagers and youngsters in school uniforms were among those detained in Wukan on Tuesday. Three rows of villagers could be seen in a police station, their wrists bound with white nylon cords.

Blue teargas cartridges could still be seen strewn in the narrow alleyways, with black burn marks on concrete.

"The whole village hasn't done anything illegal, we just want old Lin (Zuluan) to come out and to get our land back," said a villager surnamed Zhang. "But they don't care if we're guilty or not guilty. They just beat us."

Lufeng county police, who oversee Wukan, said in an earlier microblog post that 13 people had been arrested for organising illegal assemblies and using threats to force villagers to join protests. The blog has not been updated since Tuesday.

Hong Kong media have reported that the police have also televised photographs of five village protest leaders, offering 100,000 yuan ($15,000) rewards for information on their whereabouts.

A small group of Hong Kong democracy activists and politicians marched to Beijing's official liaison office in the city on Wednesday to show solidarity.

Legislator Kwok Ka-ki warned that Hong Kong people must not remain silent, saying Hong Kong could one day face a similar crackdown.

Chinese state media coverage of Wukan has been limited to brief statements from the local government, posted on social media, about the unrest. The comment function has been disabled under many of those reports.