Christchurch police have charged a man in relation to a serious assault, which left a person critically injured

Emergency services were called to Hereford Street, just after 4am yesterday - where it's believed a stabbing took place.

Police say initial indications suggest those involved were known to each other.

Two people were taken to Christchurch Hospital - one with critical injuries and another with serious.

A 22-year-old man is due in court today, charged with wounding with intent to cause grievous bodily harm.