Four women whose bodies were found in the trunks of burning cars over the last two weeks have been connected to adult advertisements on, police said Monday.

The two most recent victims were found early on Christmas morning, bodies burned beyond recognition, police said. Two other victims were discovered a week prior to Christmas.

All four of the women were black females in their 20s, and police said they did not appear to have been physically abused. A coroner had yet to determine the cause of death.

All of them have since been linked to "prearranged adult dating services" offered by Backpage, which supplies classified advertising services to dozens of alternative weekly newspapers nationwide.

The site offers a range of classified advertising, including traditional dating ads and ads for "escorts" and other adult-related services.

While Backpage has not yet commented on the Detroit killings, the site says it responds immediately to police requests and offers a reporting service for users who feel they've uncovered a scam or criminal enterprise.

(H/T: CNN)

Photo: Flickr user edkohler.