CALGARY -- A Good Samaritan who stopped to help four women by an apparently broken down car was robbed and assaulted west of Calgary.

RCMP say the woman was driving east on the Trans-Canada Highway near Highway 68 on Saturday when she saw four women standing beside a car with the hood up.

The women waved her down so she stopped to offer assistance.

Police say she got out of her vehicle and was assaulted by one of the women, and then all four women got into her car and drove away.

The victim's vehicle was located a short time later on the Stoney Nakoda First Nation and police say it refused to stop and the suspects fled into the woods.

Karine Beaver, 25, and 27-year-old Michelle Twoyoungmen, both from the Stoney Nakoda First Nation, have been charged with robbery and possession of property obtained by crime.

RCMP say the vehicle the four females had been standing next to was stolen from Calgary the previous day.