A stranger stabbed a pregnant woman and removed her baby from her womb after the victim answered a Craigslist ad in Colorado, authorities said.

Police were called to a home after a stabbing Wednesday afternoon in Longmont.

When they arrived, they heard a woman inside screaming for help, Longmont Police Cmdr. Jeff Satur said.

Officers entered the home and found the 26-year-old woman with stab wounds in the stomach. They then found out she had been pregnant, and the baby had been removed, authorities said.

“It’s a difficult day for a lot of people,” Satur said.

The victim, who was seven months pregnant, was responding to a Craigslist ad to buy baby clothes from the suspect when the attack occurred, according to Satur.

“When she got here, she was assaulted and stabbed, and her baby was removed,” he said.

The victim was transported to Longmont United Hospital, where she underwent surgery and was expected to survive.

In a strange twist, police said the 34-year-old suspect arrived at the hospital with the baby at the same time, claiming a miscarriage. The baby did not survive.

Detectives are searching the suspect’s home. The names of the two women have not been released, but Satur said they did not know each other.

Update: Suspect Accused of Cutting Fetus From Pregnant Colorado Woman’s Womb Is ID’d by Police

The suspect faces charges of attempted murder, assault and child abuse.

Some police stations have started offering “safe zones” for online sellers and buyers to conduct their transactions after recent deaths linked to the classified advertisements website.