Protesters have clashed with large numbers of police over the planned demolition of a mosque's dome in a largely-Muslim town in Yunnan, China.
Social media videos showed crowds outside the 13th-century Najiaying Mosque in Nagu town on Saturday.
Scuffles broke out between police and locals, who were hemmed in by hundreds of armed officers.
Yunnan, an ethnically-diverse province in southern China, has a significant Muslim population.
China is officially atheist and the government says it allows religious freedom. But observers say there has been an increased crackdown on organised religion in recent years - with Beijing seeking greater control.
In Nagu, the Najiaying Mosque had been a key landmark and in recent years had expanded with a new domed roof, as well as a number of minarets.
However, a 2020 court judgement ruled the additions illegal, ordering them to be removed. Recent actions to carry out that order appear to have sparked the demonstrations.
Videos of Saturday's protests, verified by the BBC, showed lines of police blocking entry to the mosque, and group of men attempting to force their way in with some throwing rocks at police.
Other clips show the police later withdrawing, as the crowd enters Najiaying Mosque.
Police in Tonghai County, where Nagu is located, issued a statement on Sunday calling for protesters to surrender to police by 6 June. Dozens have been arrested so far.
"Those who voluntarily turn themselves in and truthfully confess the facts of violations and crimes may be given a lighter or mitigated punishment," said the notice.
Calling the incident "a serious obstruction of social management order", authorities also urged others to "actively report" protesters.
Protests in China remain relatively uncommon, but more have taken place since the pandemic where severe lockdowns and movement restrictions triggered displays of public anger.
The Hui are one of 56 ethnic groups recognised by Beijing and are predominantly Sunni Muslims. Yunnan, in the country's south-west, is home to some 700,000 of about 10 million Hui Muslims in China.
They are often referred to as Chinese Muslims by local media, and are seen as well-integrated into Chinese society after centuries of intermarriage and assimilation.
Observers say Beijing has sought to have more control over religious groups in recent years - and how they operate in society.
In 2021, President Xi pledged to continue a "Sinicisation of religion" - the transformation of religious beliefs to reflect Chinese culture and society.
In 2018, hundreds of Hui Muslims in the Ningxia region engaged in a protracted standoff with authorities to prevent their mosque being demolished. Authorities later relented but insisted that its Arabesque features must be altered.
That same year, three mosques in Yunnan were also shut down for what was deemed to be "illegal religious education".
China has also been accused of systematic human rights abuses against Uyghur Muslims in its north-western province of Xinjiang, where mosques have been demolished and Islamic religious practices banned. Beijing denies the accusations of abuse.