Russian police discovered the dismembered remains of six children killed with an axe after the alarm was raised when the youngsters failed to appear at kindergarten.
Officers broke in to the family flat through a window to find the dead youngsters - aged between one and seven - and the body of their pregnant mother in Nizhny Novgorod, east of Moscow.
All had been hacked to pieces with an axe and bundled into plastic bags, said police.
Locals said the father had been ex-communicated from the Seventh Day Adventists religious group for allegedly committing adultery, according to major Russian news website LifeNews.
The children's 51 year old father, named as Oleg Belov, is suspected of killing his family at their home in the city of Nizhny Novgorod, 250 miles east of Moscow, said official sources.
The children were named as Alyona, seven, Fyodor, six, Sonya, five, Nikifor, three, Ilya, two, and Daria, one.
Their mother was named as Zinaida, a lecturer in advanced mathematics at a local university.
The alert had been raised by the kindergarten and Zinaida's mother Valentina Zaitseva, 69, after the children were not seen for a week, after not attending classes since 25 July.
The Kremlin's children's ombudsman Pavel Astakhov said that it appeared the mother intended to deprive Belov of his paternal rights, barring him from raising the youngsters.
Police yesterday launched a murder probe with reports emerging last night that the father may have been found in a mental hospital.
Neighbors claimed that the father had been seen at the flat, but left in an unknown direction. It is unclear when the sighting of the father took place.
NTV channel have reported that the murdered mother had been pregnant at the time of her death.
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