Image copyright AFP Image caption Yang Maodong, known as Guo Feixiong, had served an earlier five-year term

Leading Chinese rights activist Yang Maodong has been sentenced to six years in jail for disturbing public order.

Mr Yang, 48, better known by his pen name Guo Feixiong, had been detained since organising a week-long peaceful protest outside a newspaper office in the southern city of Guangzhou in 2013.

Amnesty International branded the sentence "a clear-cut act of political persecution".

Two other activists Liu Yuandong and Sun Desheng were also jailed on Friday.

Yang Maodong had helped organise a press freedom protest outside the Southern Weekly in Guangzhou in January 2013, after its reporters complained that the newspaper's New Year message urging stricter adherence to the constitution had been changed by censors.

He also encouraged activists to hold up placards in several other cities.

'Dark day'

Mr Yang, who had previously been imprisoned for five years after campaigning against corruption, has been held in detention for two years since his arrest, amid boycotts by his lawyers over procedural issues.

Mr Yang's lawyer, Zhang Lei, told Reuters on Friday: "He wasn't guilty of anything at all. This sentence is unacceptable and unfair."

Image copyright Reuters Image caption The Southern Weekly was embroiled in a censorship row over a New Year message

Mr Yang's sister said the trial amounted to "cruelty and political persecution".

Another of his lawyers, Li Jinxing, said that minutes before the trial the court in Guangzhou had added a charge of provoking troubles, which allowed for a longer sentence.

Roseann Rife, East Asia research director at Amnesty International, said: "It's a dark day when people advocating for press freedom and democracy are subjected to torture and other ill-treatment and sentenced to lengthy prison terms after sham trials."

Sun Desheng was jailed for two and a half years and Liu Yuandong for three years for disturbing public order.

Chinese judicial officials have not commented on the sentences but in similar cases the foreign ministry has urged other nations to respect China's judicial sovereignty.

On Thursday, a court reduced the sentence of prominent journalist, Gao Yu, 71, for leaking state secrets from seven years to five and allowed her out of jail on medical grounds.