Police opened a murder investigation on Friday after alleged arson killed a couple and seven children during a house fire in a village near the central Russian city of Perm.

"According to the preliminary results of an examination of the scene, the cause of the fire was arson," the Russian state investigations committee said on its website.

"As a result, the building was filled with smoke. A 34-year-old man, his wife and seven children aged from four to 13 years died from carbon monoxide poisoning," the statement said, adding that an investigation to confirm the causes of the fire in the village of Mokhovoye was continuing.

"All the circumstances of what happened are being established, including the reasons leading to the tragedy," the statement said.

Five more children also died in two separate house fires in the provincial towns of Pugachev and Khvalynsk in the Saratov region overnight, Russian agency RIA Novosti reported without indicating what caused the blazes.

The mother of three of the children also died in one of the fires.

(residential fire photo via Shutterstock)