Five workers at a Taiwanese-owned shoe factory in southern China have been convicted for taking part in a protest against wages and conditions.
Four were sentenced to up to three and a half years' jail, while a fifth was given a suspended sentence, a New York-based labour rights group said.
The five were among 40 arrested after thousands of workers went on strike at two factories in Dongguan in April.
A court official said the five were sentenced for "destroying property".
Court documents said they caused 153,534 Yuan (US$18,600) of damage at the factory, owned by Stella International. According to New York-based China Labor Watch, the factory makes shoes for international brands such as Brown, Wolverine World and Timberland.
Robin Munro, research director at the Hong Kong-based China Labor Bulletin, said the five took part in a protest at a shoe factory in Dongguan on 23 April over their working conditions. They were being paid 450 Yuan ($54) a month, and much of that they had to use to pay for food and accommodation at the factory, he said.
Mr Munro said that the prosecution had produced no evidence to show these workers were responsible for the damage.
They have been in detention since April, he said.
Separate trial pending
Another five workers were arrested at a different factory in Dongguan after a separate protest on 21 April, and they are expected to stand trial soon.
Many protests in China happen far from the public eye, but recent figures show they are on the rise.
More than three million people took part in protests in China last year - an increase of almost 15% over the year before - according to official statistics released in June.
The figures confirm police reports that demonstrations within China are growing in size and number, and becoming better organised.
The main problems are reported to be wage disputes, social welfare problems, the restructuring of state-owned enterprises, and evictions.