A Mexican couple have admitted to killing at least 20 women after being caught transporting human body parts in a baby stroller.

Juan Carlos and his wife Patricia, who have only been identified by first name, were detained on Thursday in Ecatepec - a crime-ridden suburb of Mexico City - after officers caught them coming out of a house with a stroller full of dismembered body parts, officials say.

After searching two buildings, investigators found additional human remains in buckets filled with cement in a vacant lot and the rest wrapped in plastic in a refrigerator near their home.

The pair are also suspected of selling one of the dead women's baby and the bones of at least one of the victims.

Forensics experts are attempting to identify the victims while the couple remain in detention and the investigation proceeds.

A Mexican couple were arrested Thursday in Ecatepec - crime-ridden suburb of Mexico, City, - while transporting body parts in a stroller

Juan Carlos and his wife Patricia, who have only been identified by first name, admitted to killing at least 20 women

Patricia is seen pushing the dismembered body parts from a home where the rest were discovered in buckets of cement and a freezer

The child of slain Nancy Huitron, who disappeared in September, was sold to a couple who has now been arrested.

Juan Carlos is pictured pushing a hand truck while his wife transported body parts in a stroller

The baby has been found and returned to her maternal grandmother

Juan Carlos and Patricia came under suspicion because they knew three of the women who had disappeared over the last six months in the city. Police had placed them under surveillance when they caught them Thursday.

Arlet Samanta, Evelyn Rojas, and Nancy Noemi all went missing this year in April, June and September.

Juan Carlos also admitted to sexually abusing at least one of his victims before killing her.

Police discovered eight 20-liter plastic buckets filled with body parts buried in cement at two locations in Jardines de Morelos.

A psychiatric evaluation showed both Juan Carlos and his wife to have mental disorders and dissiative personalities.

They sat stone faced while in court and have reserved their right to testify.

Hundreds of people vented their outrage in the streets of Ecatepec on Sunday.

Carrying candles and white flowers, they demanded justice and an end to rampant femicide in Mexico state.

'Not one more! Enough is enough!' said their placards

Women lay flowers for the victims Sunday after the couple were detained

Mexico has suffered for years from waves of violence against women and girls and more than 90 percent of crimes go unpunished in the country, pictured is a March protest in Mexico City with a banner that reads,' Femicides, Negligence, Violence, Inequality'

Mexico has suffered for years from waves of violence against women and girls and more than 90 percent of crimes go unpunished in the country.

According to UN Women, seven women and girls are killed in Mexico each day.

The local non-governmental organization Semaforo Delictivo recorded 188 killings of women in the country between January and March this year - an 18 percent increase from the same period last year.

In past years, Ciudad Juarez, on the border with the United States, was a focal point for the killings and disappearances of women, but Ecatepec too has become an epicenter of the violence.