It's having her children not crying every night and asking if they will be killed is why Kateryna Halenda knows it was the right call to flee Ukraine.

Leaving a country torn apart by war may seem like an easy decision but husband Oleh had to persuade her to leave with their two young children because she didn't want to leave him behind.

Kateryna now knows she and her kids are safe but still gets mobile phone alerts when air raids are happening back home.

Her worries remain, hoping Oleh is ok.

The 32-year-old teacher and her two sons Oleksander, nine, and four-year-old Artem are three of the more than five million refugees to have fled Ukraine while worried about the family they've left behind.