"We are seeking assistance from anyone who may have seen this vehicle at this location, or was at the vicinity at the time and may have seen the female or male near or inside this vehicle to come forward with any information."
She said there had been no arrests yet.
On Thursday, a group of men tried to pull a 24-year-old woman into a van while she was walking along Francis Hicks St towards the Hastings cemetery.
The woman told police the silver people mover pulled up next to her, and a male in the back opened the rear door and asked for directions.
The man said he could not hear her, so she moved closer and the man grabbed onto her pants and tried to pull her into the vehicle.
She fought back and managed to break free, but told police she fell over in the process, and believed she may have been knocked out.
The vehicle was described as a long silver van or people mover, possibly a Toyota Lucida, with sliding doors on both sides at the back.
The three occupants were described as dark-skinned.
The male in the back was wearing a green T-shirt, black jeans, Red Band gumboots and had a tattoo on the back of his left hand.
Ms Williams said the two incidents were not related.
Last week police issued a public notice about a cyclist "grabbing" female joggers.
A 16-year-old was running on Southland Rd, Hastings when a young man on a bicycle tried to grab her around the waist, but fell off. He then chased her until she ran into a nearby dairy.
At 6am Tuesday a woman in Taradale reported a young man frequently circling around female runners on his bike, making them feel uncomfortable.
- Anyone with information on Wednesday's allegation of sexual assault should contact Ms Williams on 0211913294, or Constable Rhyan Honeyfield on 06 8310700 with information regarding the other incidents.
