Clips shared on social media in China have appeared to show fresh protests against Covid restrictions, after an apartment block fire killed 10 people.
Demonstrators were filmed confronting officials, breaking down a barrier and shouting “end the Covid lockdown”.
Beijing continues to pursue a zero-Covid policy, despite record infection numbers and growing public anger.
Authorities in the city of Urumqi have denied claims that restrictions stopped people escaping Thursday’s fire.
The capital of the western Xinjiang region has been under restrictions since early August.
The BBC was earlier told by one resident that people living in the fire-hit compound were largely prevented from leaving their homes.
That has been disputed by Chinese state media. However, Urumqi authorities did issue an unusual apology late on Friday – vowing to punish anyone who had deserted their duty.
Footage shared on Friday night showed residents, many of them in face masks, gathering after dark on the city streets.
They were seen chanting, pumping their firsts and arguing with officials. The location was verified by the Reuters news agency.
One demonstrator shouts through a megaphone, and in another clip, a crowd breaks through a barrier policed by city workers wearing protective gear.
Live streams monitored by the BBC on Friday night also appeared to show protesters gathered on the steps of a city government building.
The internet is heavily censored in China, and references to the Urumqi protests had largely been taken down by Saturday morning.
Local media said Thursday’s deadly blaze at the Urumqi apartment block – which also injured nine people – appeared to have been caused by a fault with an electrical extension.
Online posts have suggested that firefighting efforts were hindered by Covid restrictions.
This was denied late on Friday by city officials, who sought to blame parked vehicles for stopping firefighters’ access to the burning building.
Protests are rare in China, although there has been mounting public dissent aimed at Beijing’s zero-Covid strategy.
This is the last policy of its kind among the world’s major economies, and is partly due to the country’s relatively low vaccination levels and an effort to protect elderly people.
Snap lockdowns have caused anger across the country – and Covid restrictions more broadly have trigged recent violent protests from Zhengzhou to Guangzhou.
In spite of the stringent measures, China’s case numbers this week hit all-time records since the pandemic began.
The Xinjiang region is home to many Uyghurs, against whom the Chinese government has been accused of committing numerous human rights abuses – something it denies