A police officer was bitten as she was trying to explain to a man why he should not visit other people's homes during the coronavirus pandemic.
It happened after officers were called to a disturbance at Drake Street, Rochdale, at 18:40 BST on Thursday.
As police were speaking to a man about government guidelines around Covid-19, two officers were punched and one, aged 21, was also seriously bitten.
A 29-year-old man was arrested on suspicion of a number of offences.
Supt Richard Hunt, from Greater Manchester Police, said: "No police officer should have to come to work - doing a job to serve and protect our communities - and be assaulted.
"It is absolutely disgusting that my officer was faced with this and all of our thoughts are with her as she rests at home.
"Having spoken to the officer earlier this morning, she said that last night's incident was a stark contrast to the support she has felt over the past few days."
The suspect remains in police custody after being arrested on suspicion of criminal damage, domestic violence assault, section 18 assault with intent to resist arrest and regulation 8 of the Health Protection Regulation 2020 (Coronavirus).