Protests against Covid restrictions in China appear to have intensified following a fire which killed 10 people in an apartment block in Urumqi.
In the city of Shanghai, videos posted on social media by foreign journalists show hundreds of people calling for President Xi Jinping to stand down.
People were seen lighting candles and laying flowers for the victims.
Students also gathered at many universities to remember the victims of the fire in the Xinjiang region.
Many people have blamed their deaths on the lockdown of residential buildings - something Chinese authorities have denied was the cause.
At the gathering in Shanghai, people were heard shouting slogans such as "Xi Jinping, step down" and "Communist party, step down". Some also held blank white banners.
Though the situation in the area had calmed by Sunday morning, the BBC saw a heightened police presence in the area of the protest, with several dozen police officers, private security guards and plain-clothed police officers on the streets.
Elsewhere, in several Chinese universities, photos and videos emerged online of students protesting on Saturday night. The largest gathering seemed to be at Nanjing Communications University.
The videos are difficult to independently verify, but many of them suggest there has been a real shift in people's mentalities.
The open display and demand for President Xi to resign is the most explicit and outspoken criticism we have ever seen in an otherwise extremely benign and obedient Chinese society.