A Beijing court has sentenced 10 people for illegally detaining petitioners.

Chaoyang District People's Court announced the verdict on Tuesday to the 10 defendants ― who included three minors ― from Yuzhou city in Henan province.

Defendants were given sentences ranging from six months to two years for illegal detention. The juveniles were placed on probation, the court announced.

Experts said it is one of the most high-profile cases involving "black jails" ― places used for illegal detention ― in recent years.

In February 2012, Wang Gaowei, the principal defendant, rented two yards in Wangsiying township in Beijing's Chaoyang district and hired people to detain petitioners from Henan, according to a statement provided by prosecutors.

On April 28, four petitioners, who intended to appeal to higher authorities in the capital for help, were brought to the yards by car. Wang and the other nine defendants did not allow them to leave until midnight on April 29, the court said.

Those detained were then escorted back to their hometown, but later returned to Beijing and reported the case to police, the court said.

On May 2, Beijing police arrested the defendants at the yards and freed some people who had been detained, the court said, adding that the longest period of detention was six days.

But the court did not reveal more information about the 10 defendants ― who they are, why they detained these petitioners, or if they are employed by someone else to do so.

Announcing the verdict, the court said the 10 defendants had damaged other people's rights, thus committing the crime of illegal detention. But it gave them lighter punishments after they confessed at the trial and said they were willing to compensate the victims.

Wang was sentenced to two years, the heaviest sentence, while all 10 defendants were ordered to pay compensation ranging from 100,000 yuan ($16,000) to 610,000 yuan to the victims, the court said.

On Dec 2, the case caught public attention after local media published a report saying the 10 had been placed on trial for illegal detention. But the report was soon denied by Beijing's high court and was deleted from the Web.

Guo Jingxia, head of the information office with Beijing High People's Court, confirmed that information on the case had been disclosed previously. But the court had not delivered a verdict as media reported, and some facts in the report were not true.

The report said the principal defendant had been sentenced to 18 months in jail.

"The case got a lot of attention about two months ago, especially on micro blogs, and now I'm glad to see it has ended with a clear result," Guo said, adding it is not the first case where municipal judicial bodies have handled incidents involving "black jails".

In June 2012, Changping District People's Court punished a gang of nine who stopped petitioners in the city, while prosecutors in Daxing district of Beijing dealt with at least six cases involving more than 13 people who blocked and detained petitioners in 2010.

Petition offices at all levels nationwide are measured with a point system. Points are deducted if local residents take their petitions to higher authorities, to urge local authorities to solve people's problems where they occur. But the point system prompts some local officials to stop petitioners from going to higher authorities, which have led to public criticism for years.

Han Yusheng, a professor of criminal law at Renmin University of China in Beijing, said the Chaoyang court's verdict will warn provincial governments not to deal with petitioners in a negative way.

"Some governments intended to use money to solve conflicts between authorities and residents, and restrict petitioners' acts, but on the contrary this created more disputes," Han said.

Under China's Criminal Law, those who restrain the personal freedom of others face up to three years in jail, with the punishment mainly depending on the length of the detention, Han said.

Yu Jianrong, a professor at the Rural Development Institute under the Chinese Academy of Social Sciences, said the verdict reflects that petitions in China should be regulated according to the law.

Yu said other problems related to petitioners, such as why local governments arrange for people to block petitioners in Beijing, and how to improve the relationship between the public and authorities, are more worthy of consideration.