A 9-year-old boy who was severely injured in a passenger plane crash in Russia died on Wednesday, bringing the death toll to 45.

Anton Terekhin died overnight in a hospital in Petrozavodsk, the regional branch of the Emergency Situations Ministry said on its website.

The Russian-made Tu-134 which crashed in heavy fog on late Monday was heading towards the city of Petrozavodsk from Moscow.

Eight were reported to have survived with serious injuries. The ministry said the boy died of his injuries early Wednesday. His mother and 14-year-old sister survived.

Russia's Deputy Prime Minister Sergei Ivanov on Tuesday said that the initial information indicated the crash was caused by the pilot as he missed the runway due to
adverse weather condition.

It was the deadliest air disaster in Russia since Polish President Lech Kaczynski's official plane crashed near the western city of Smolensk in a thick fog in April 2010, killing him and all 95 others on board.