In the southern city of Odesa, a woman and her young child, both struggling not to break down, look out the window of a departing train as the woman’s grandmother, a tissue pressed against her face, bids them goodbye from the platform.

In the western city of Lviv, a bearded man places his hand up to the outside of a train window while a young child sobs from the other side moments before they are to part from one other.

A woman who has fled Ukraine sits amid throngs of other refugees after arriving at a train station in Poland, her head in her hand and her eyes staring resignedly into space.

Most of the more than 3.5 million refugees fleeing Ukraine have been women and children because men ages 18 to 60 – fighting age – are forbidden to leave the country.

The millions who have left Ukraine since Russia’s invasion began have made their way on foot, by rail, bus or car to neighbouring countries such as Poland and Romania before some travel on across Europe. Most, however, have not done so.

While fewer have crossed borders over the past week, the scale of the task of providing homes to those seeking safety in the European Union is becoming increasingly apparent, above all in Eastern and Central Europe.

Poland, home to the biggest Ukrainian diaspora in the region before the war, has taken in more than 2.1 million people and while some plan to head elsewhere, the influx has left public services struggling to cope.