BEIJING (AP) -- Police in a southern Chinese city detained 18 people after a protest against a planned chemical plant turned violent over the weekend, local authorities said Thursday.
The suspects were accused of disrupting order and causing trouble, according to a transcript of a news conference provided by the Communist Party newspaper People's Daily.
Another 15 people, including four police officers, were hospitalized with injuries, but no one died from the protest violence, contrary to some media reports, health officials said.
More than 1,000 people gathered in front of Maoming city's Communist Party offices on Sunday to protest plans to build a plant to manufacture paraxylene, a chemical used in the production of plastic bottles and polyesters.
Similar plants have been opposed across China because of health concerns, especially among members of the country's growing middle class. The opposition has posed a challenge to local officials, who must balance between economic development and environmental protection.
The protest was initially peaceful but turned violent after police reinforcements arrived and tear gas was fired to disperse the demonstrators.
At around 10 p.m., about 20 people on motorbikes threw bricks, stones and bottles at riot police, destroyed traffic signs and set fire to roadside police booths, eyewitness Chen Yifeng told The Associated Press.
Deputy Mayor Liang Luoyue said Thursday that some hooligans took advantage of the situation, overturning a private vehicle, attacking the party offices with stones and glass bottles, and smashing shops.
"Such acts severely violated the state law, badly disrupted social order and affected the normal work and living of local residents," Liang said.
Human Rights Watch urged Beijing to investigate possible excessive force by police.
Deputy police chief Zhou Peizhou said police did not beat anyone to death but that they could have accidentally hurt bystanders in dispersing the crowds.
Chinese authorities have called for the public to exercise reason toward such chemical plants, arguing paraxylene is not as dangerous as perceived.
But any explanation will be met with resistance because the government is so distrusted, said Wu Yixiu, head of toxics campaign at Greenpeace East Asia.
"The protest is no longer about whether the project is toxic or not toxic. It is no longer a mere environmental issue but a social phenomenon," Wu said. "It reflects deep distrust in government, which — by supporting those projects to start with — has failed to be a neutral arbiter and lost its credibility."
The government needs to be transparent and involve the public in the decision-making process to regain trust, she said.
"The public will only say yes when they have the chance to say no," Wu said.