An officer sustained a minor injury when police tried to break out a house party in Lincoln on Wednesday night.
Three young men men were arrested and many other were pepper-sprayed in the operation.
Lincolnshire Police were called to the house party in St Margaret’s Garden off Hykeham Road to respond to a report of a brawl involving drunken youths and that a young girl had been attacked.
When officers attended there were believed to be over 100 people present.
Police say they were met with aggression by a substantial number of individuals who threw cans and bottles in their direction.
Several young people were pepper-sprayed and three 16-year-olds were arrested and remain in custody.
One officer sustained a minor injury, the force clarified.
Detective Inspector Dave Harrop said: “It is very rare that we have to attend a party that has got out of hand, public safety is a priority and we will always take appropriate action to protect people.
“On this occasion officers attended to investigate and prevent offences as well as ensuring that there weren’t any individuals who would require medical treatment.
“I’m disappointed by the violence shown towards our officers and we will be investigating this thoroughly.
“All of our officers wear body cameras so we are reviewing footage captured during the incident to see if there were any further offences.
“Anyone who was at the party or lives locally and has their own footage, images or information needs to pass this to us to help our investigation. This will help us minimise the chances of this happening again.”
Anyone who attended the party and has information that will assist with the investigation should call Lincolnshire Police on 101 quoting incident 390 of February 14.