Seven police officers have been injured while breaking up a "completely unacceptable" house party.
Police estimated about 40 people were at the gathering in Nottingham just after midnight on Wednesday.
Drone footage shared by Nottinghamshire Police showed a stream of people sprinting away from the property as officers arrived.
The force said bottles were thrown at officers and a police dog but there were no serious injuries.
Two men, aged 26 and 21, and a 17-year-old girl were arrested on suspicion of common assault of an emergency worker.
The 26-year-old was also held on suspicion of possession of cannabis.
Another 26-year-old man was arrested on suspicion of being in charge of a vehicle while unfit through drink.
Officers also issued 10 £800 fines to people for breaching Covid-19 regulations related to the illegal gathering in Woodborough Road, Mapperley.
Assistant Chief Constable Steve Cooper said: "This incident was completely unacceptable.
"An investigation is ongoing as to who else may have been present and we will take robust action against those found to have committed offences.
"Covid or no Covid - assaults on emergency services staff will not be tolerated and as well as receiving fines, the individuals involved in this incident will be liable for prosecution for other offences."
Seven of the top 20 areas in England for high coronavirus infection rates are in Nottinghamshire and Leicestershire, according to latest figures.
Ashfield, Mansfield, Gedling and Nottingham all feature on that list with rates above the national average in the week up to 27 February.
The force added health chiefs are worried the numbers are not coming down at a fast enough rate compared to other areas.