Updated

Two men were held for questioning Tuesday as part of an investigation into the slayings of four Detroit women whose bodies were found in car trunks after three of them placed online escort ads, police said.

The men, ages 32 and 24, were arrested Tuesday morning by members of a federal and local law enforcement task force in Sterling Heights, a mostly middle-class community north of Detroit. They had not been charged by late afternoon, Detroit police Sgt. Eren Stephens said. Police also searched a Sterling Heights home.

The men were "placed in police custody for questioning in regard to the Backpage cases," Stephens said.

Detroit Police Chief Ralph Godbee has said three of the slain women had placed ads for "prearranged adult dating services" on Backpage.com, prompting investigators to publicly say late last year that someone may have been targeting escorts.

Godbee had stopped short of saying the slayings were the work of a serial killer.

Little other news about the cases had surfaced since the women's bodies were found in December.

The bodies of 24-year-old Demesha Hunt and her 23-year-old cousin, Renisha Landers, were found Dec. 19 in separate car trunks in Detroit. The bodies of two more women — friends Natasha Curtis and Vernithea McCrary — were found Christmas Day in the trunk of burning car parked in a garage.

Relatives have said Hunt and Landers were not escorts.

Backpage.com said in late December that it had provided police with information about ads that a suspect may have posted on numerous websites.

It had come under criticism last year when attorneys general for 45 states raised concerns about how the site policed ads for adult services.

Other online sites also have been used to post pay-for-sex ads. Such sites also have been used to lure in crime victims.

Three men were killed last year in a robbery scheme after answering ads on Craigslist that promised work on a nonexistent cattle farm in southeast Ohio.

Two Detroit men were convicted last year of murder in the ambush slaying of a man at a suburban motel. The victim went to the motel in June 2010 with the promise of a romantic encounter with a woman he met online. The man was then robbed and killed.