Wellington Police are investigating a sexual assault that occurred in Tawa this evening.

At approximately 7.25pm on Monday, a woman was walking north on Duncan Street, near the overbridge to the Tawa Railway Station.

She was grabbed from behind by a male who then indecently assaulted her.

When the female reacted to the male's actions he ran south on Duncan Street towards Tawa College.

The victim did not see where he ran to after that.

The male is described as being approximately 5'7” tall, and of medium build.

He was wearing a grey hooded sweatshirt and a pair of dark green camouflage knee length shorts.

Detective Sergeant Haley Ryan of the Wellington Crime Squad says Police are determined to find the person responsible and are asking for the public's help.

Police ask anyone who was in the area at the time and saw someone fitting this description, or who recognises this description to call Wellington Crime Squad on 3812077, or Wellington District Command centre on 04 3812000.

Source: New Zeland Police.