A 27-year-old woman threw her children from the 15th-floor balcony of her apartment building outside Moscow, showing little emotion after viewing the bodies.
Both children, 4- and 7-year-old boys, died before paramedics could arrive Sunday, RIA-Novosti reported.
A security video from the apartment building posted to LifeNews.ru showed the aftermath of the incident as witnesses frantically called for help. The mother, Galina Ryabkova, herself descended to the ground floor to observe the bodies.
Building concierge Natalia Fetu told LifeNews that Ryabkova never attempted to conceal the fact that she threw the children from the building herself and called her children "little angels, who are now flying to heaven."
Ryabkova appears calm as residents heatedly address her in the soundless video. Police and medical personnel arrive outside, covering the bodies that lay just out of camera sight with a sheet.
Investigative Committee spokesman Vladimir Markin said the woman was planning a divorce from her husband and had tried to commit suicide before her wedding. Neighbors said the children's father was away on a business trip at the time of the incident.
The family's eighth-floor apartment — the woman had climbed seven stories higher to toss the children — was discovered to be messy, disorderly and had exposed wiring.
Ryabkova will undergo a psychiatric examination and could face up to life in prison on murder charges.