Police are hunting a man whose believed to inflicted serious head injuries on a woman - and reportedly pointed a gun at those who saw it

Numerous emergency services calls were made just before 11 today after members of the public saw a man assaulting a woman on Hastings' Roberts Street.

The woman's in hospital, and the pair are believed to be known to each other.

Police want people with information to come forward -- saying a number of people saw this - some even filming it.

There will be more Police in the area as they attempt to find the man.