In one video posted on social media, a woman appears to be taking off her clothes when a number of police on horseback ride past and knock her to the ground. Screenshot / @DarkiFranky, Twitter
Wild scenes have unfolded in the European city of Brussels, where an April Fool's Day prank went horribly wrong.
Thousands of people clashed with police in a park after gathering for what they believed was a concert, despite coronavirus restrictions being in place.
Those who attended had been tipped off about a concert featuring at least eight stages and a number of DJs, but when they turned up there was no entertainment. Instead, they were met by heavy-handed police.
In one particularly disturbing video, a young woman appears to be taking off her clothes when a number of police on horseback ride past and knock her to the ground.
Bystanders rush to her aid while she lies motionless on the grass, but police do not stop to render assistance.
Belgium: A young woman seriously injured by the police on horseback! š±š I wonder, who are the real criminals? Coronavirus measures by the City of Brussels! pic.twitter.com/Q4uvat41sE
In other images, a police officer's face is covered in blood as he holds a protester on the ground.
The crowd turned on police, according to journalists who witnessed the scenes.
Projectiles were hurled at the officers who wore riot gear but needed the help of water cannons and tear gas to keep the crowd at bay in the Bois de Cambre park on the southern side of the Belgian capital.
Brussels police spokeswoman Ilse Van de keere said 22 people were arrested and several police officers were injured. She said eight partiers were wounded, including two who were taken to hospital.
The police, wearing protective helmets and advancing in a line, moved in to enforce strict Covid-19 social-distancing rules that prohibit gatherings of more than four people outdoors.
Brussels law enforcement authorities on Wednesday had issued a warning that the announcement on social media of a "party" was illegal and that its organisers could be prosecuted.
Belgium on Saturday imposed tighter restrictions aimed at curbing surging Covid infection numbers.
They include closing schools, keeping borders closed, limiting access to non-essential shops and lowering the number of people able to meet outdoors to four.
Belgium has reported over 882,000 confirmed coronavirus cases and more than 23,000 virus-related deaths.
Hospitalisations due to Covid-19 have risen in recent weeks and health authorities have warned that intensive care units could reach a critical level by April 10 if the pace of new infections and hospitalisations does not slow down.
One concert-goer, Selim Jebira, told AFP that "we were tear-gassed for no reason at all".
Brussels Mayor Philippe Close tweeted that, while he could understand people wanting to go outside in the spring weather, "we can't tolerate such gatherings".
He thanked the police "for the difficult job, and for people who have respected the rules for more than a year" since the start of the pandemic.
Another event has been advertised for Friday in another Brussels park, promoted by a group called the Abyss. The group said it does not question the Government's strategy but fights for citizens' rights to gather outdoors.
It comes as a Belgian court on Wednesday ordered the Government to draw up a pandemic law within 30 days or face the annulment of some of its anti-Covid restrictions.
The Brussels court of first instance made the order after a complaint by the Belgian League of Human Rights.
The Belgian Government appealed the decision and insisted that several other jurisdictions had greenlit the measures, a statement said.
The legal tussle matches similar battles in the Netherlands and Germany, where anger against anti-virus restrictions has also landed in courtrooms.