'Exorcism' deaths: Mother Zakieya Avery stabbed children to death 'to remove the presence of the devil'

Avery was allegedly performing an exorcism when she stabbed her two toddlers

Zakieya Latrice Avery has been charged with the murder of her two children (AP)

A Maryland mother accused of killing her two children told investigators that she thought an exorcism was necessary to remove the presence of the devil.

Zakieya Avery, 28, and her friend Monifa Sanford, 21, have been charged over the murder of one-year-old Norell Harris and two-year-old Zyana Harris after officials were called to a home in Germantown, Maryland, where both women were living.

Avery's other children, Taniya Harris, five, and Martello Harris, eight, were also injured in the attack and remain in a stable condition in hospital.

Captain Marcus Jones of the Montgomery County police department said in a press conference on Sunday that Avery told investigators that she thought an exorcism of her children was necessary to remove the presence of the devil and evil spirits.

Captain Jones says police recovered two knives from the home after forcing their way into the property, where they found Norell and Zyana. Both had suffered multiple stab wounds.

Sanford also allegedly made similar statements during questioning, police said.

In 911 transcripts released by police, a neighbour alerted authorities after she saw a knife on the floor next to a car near the property. The car door was open and covered in blood, police said. The keys were still in the ignition.

"I heard loud noises in the night," the caller said.

She added that she heard what sounded like "jumping" and "running" but didn't think anything of it because there were four children living in the home.

The women face charges of first-degree murder and attempted first-degree murder. Both were being held without bond.

Additional reporting by Associated Press