Cops fear they have a serial rapist on their hands.

Police sources say detectives determined there was just too much in common with a series of recent sexual assaults -- and the description of the suspect for them -- not to be related.

An announcement on the hunt is expected Friday morning.

The most recent incident was the rape of a 25-year-old woman who was walking back from the Heron Transitway station Monday around 10 p.m.

A man at the intersection of Lasalle St. and Aldea Ave. came up from behind, grabbed her and dragged her past the children's playground equipment at Heron Park, and raped her in the bushes.

Cops say her attacker -- described as a light-skinned man, about 6-feet tall with short dark hair with a medium, athletic build -- matches the description of a man wanted for two other recent, similar attacks, as well as possibly two others.

At the time of the attack, he was wearing a dark-coloured sweatshirt and jeans.

Some of those who live in the Neighbourhood Watch community say they were already on edge after word had spread about a man in a dark vehicle following women last Friday night.

Cops believe the man they're looking for might be involved in violent attacks going back more than a year.

In August 2012, an 18-year-old girl was assaulted by a man who forced his way into her Greenbank-area apartment.

The woman had just returned home when her doorbell rang around 3 a.m. She opened the door and the man barged into the house and assaulted her.

The woman lives in a complex near Baseline and Greenbank roads.

At the time, the suspect was described as Middle Eastern in his mid-20s, with short brown hair with tailored facial hair.

Then, just four months ago, on June 29, a 29-year-old woman was approached from behind, jumped and attacked as she left the Ottawa Athletic Club around 10 p.m.

She was walking on the path between Lancaster Rd. and Erinbrook Cres. near St. Laurent Blvd. when she was pushed to the ground and sexually assaulted.

She was eventually able to call 911 and was taken to hospital.

At the time, investigators released a sketch of the suspect and the identical description as the man from Greenbank Rd.

The image is similar to the description of the attacker the woman gave police Monday night.

She has since been treated and released from hospital.

Police are expected to explain which additional cases are connected and how on Friday. Thursday night, sources would only say there are "several" incidents which might be linked based on similarities in the way the women were attacked.

doug.hempstead@sunmedia.ca

Twitter: @DougHempstead