Chinese Covid-19 test workers clashed with police at a Covid test kit factory.
The protest started on Saturday after a sudden announcement of layoffs and disputes over wages in the south-western city of Chongqing, reports BBC.
Some videos were filmed at Zybio, a company specialising in-vitro diagnostic reagents and equipment.
China's end to its zero-Covid policy has seen requirements for negative test results dropped across the country.
Hundreds of workers could be seen gathering outside the factory, some of them shouting: "Give us our money back!"
Boxes of antigen test kits could be seen strewn on the ground.
Some videos suggest later at night some protesters threw chairs, crates and traffic cones at a group of riot police deployed at the scene, forcing the officers to retreat.
Although political demonstrations are rare in China, protests over labour issues and demonstrations targeting specific companies occur frequently.
China's rigid zero-Covid policy eventually led to widespread protests in November.
Bd-pratidin English/Golam Rosul
