As soon as President Vladimir Putin announced a "partial mobilisation" for the war in Ukraine former Russian army officer Alex jumped in his car and drove to Finland with a single suitcase.

"I don't want to be killing my Slav people, my brothers, my sisters," the middle-aged man tells AFP from a modest hotel room in Finland, where he arrived on Thursday.

"I am physically disgusted to be in the presence of our Russian citizens who support the war", the IT engineer says.

The Crimea-born middle-aged man spoke to AFP on condition of not revealing his full identity, fearing for his wife and child left behind in Russia. 

"They are hostages, if I show my face they will be facing prison," he says.

Because of his military background, Alex fears he is among those Russia wants to send to the frontlines.

- 'First to be under threat' -

"I was in the army for eight years ... I have an officer's rank. I am the first to be under threat."

"Everything changed" for him when he participated in a protest in Saint Petersburg the day after the mobilisation and saw how few Russians joined in. 

He says he realised that there was "nothing left to do" for Russia and became convinced the country would fall apart.

"I know what the Russian army is like from the inside, I am deeply convinced that Putin will lose.

"Slaves who don't want to fight will never defeat anyone in their lives," he explained.