Police and a third party were called to an address on Noel Park Road, Wood Green, at 7.20pm on Friday, August 6 after concerns for the welfare of residents.
Whilst in a communal area, a man approached two officers before assaulting them and the 61-year-old man who was with them.
The man suffered stab injuries and his current condition is unknown.
One of the officers sustained slash injuries that are not life-threatening.
All three remain in hospital and are receiving treatment.
A man was arrested at the scene on suspicion of assault and two other people were subsequently arrested as part of the investigation.
All three remain in custody.
A crime scene remains in place and enquiries continue to establish a motive, the force said.
Anyone with information is asked to call 101 quoting reference Cad 2347/05Aug or Crimestoppers anonymously on 0800 555 111.
