A policeman was knocked out and two other officers injured when they were attacked by a mob of about 20 people, following a child's birthday party in Christchurch.
All three were taken to hospital with head injuries, after what neighbours said was a birthday celebration for a six-year-old that escalated into violence at a Linwood residence about 6pm last night.
Eight people were arrested after police received several reports of fighting in the area, including reports of an axe being used. Five men will appear in Christchurch District Court this week.
Two youths were also arrested and will be referred to Youth Aid.