More than 5 million Ukrainians have left their country since Russia invaded.

The number of refugees quickly surpassed the United Nations worst-case estimate, triggering a crisis in Eastern Europe as most have landed in bordering countries.

More and more Ukrainians are still in the country. More than 6 million people had been displaced within Ukraine by the end of March, according to the UN refugee agency.

One of those families told Insider that they had to leave their hometown of Kharkiv in the first week of the war after days of shelling by Russian forces.

Some of the worst bombardment has taken place in the city of Kharkiv.

Sergey Osyka said in an interview with Insider that the decision to leave was very hard.

While their sons were living in Norway, Sergey and his wife, Inna, were in Kharkiv. Despite living in a state of alert for years due to fighting in the Donbas region, Sergey was shocked by the way the shelling started.

They hid in their basement for the first six days of the war, without internet or cell reception.

I was worried when I couldn't get in touch with my parents.

Inna Osyka in the basement of their home in Kharkiv, Ukraine, sheltering from Russian bombardment.
Inna Osyka in the basement of their home in Kharkiv, Ukraine, sheltering from Russian bombardment.
Courtesy of Sergey Osyka

When Sergey and Inna decided to leave the city, Russian forces were still bombarding it. They waited for a brief break in the attacks and set off from Kharkiv in their car, unsure of where they would go.

The couple were trying to find a place to stay in western Ukraine. The war updates helped his parents coordinate the safest route.

Sergey said that they knew it was roulette because Russia shoots civilians.

Peaceful scenes in Ukrainian cities that haven't been attacked feel 'unreal'

Sergey and Inna were able to make it to the city of Chernivtsi in southwestern Ukraine, where they are temporarily renting an apartment.

They don't know what to think when they wake up and don't know if Russian shelling will spread to where they are. My son told me that my already grey head was as if it was sprinkled with ashes, Sergey said.

The couple tries to go about their day as normal. They are still able to work from home. They try to do things that were normal before the war, but knowing what is happening just a drive away makes for a weird experience.

Sitting on a bench in the park, I watch happy children playing, elderly couples walking with dogs, and it seems to me that I am behind the screen of a large TV, and look at the peaceful life that is passing by.

Inna and Sergey Osyka in Kharkiv, Ukraine, a few weeks before the war began.
Inna and Sergey Osyka in Kharkiv, Ukraine, a few weeks before the war began.
Courtesy of Bogdan Osyka

Even though they are in a city that is not under attack, Sergey and Inna said that they still feel anxious even though they are asleep.

Their lives are filled with uncertainty over what each day will bring and how much damage will be done in Kharkiv, where they are eager to return once the war is over.

My city is destroyed, residential infrastructure is destroyed, shops, schools, hospitals are bombed, and I am horrified by the thought of what I will see when I return.

The future of the city and its residents is uncertain as Russian forces focus their efforts on eastern Ukraine.

The end of the war and peace for Ukraine is the only thing that Sergey dreams about right now.

When the war ends, his father wants to start a normal life in the place where he was born.

Sergey and Inna are certain that they will return to their house in Kharkiv, where they raised their sons, as long as it is still standing.

Do you have a news tip? Contact the reporter at kvlamis@insider.com.