Thousands of refugees fleeing Russia's invasion of Ukraine have arrived in Budapest after abandoning their homes fearing for their lives as they seek safety elsewhere.

An AFP photographer saw dozens of refugees disembarking from trains arriving every 30 minutes in the Hungarian capital from the Ukrainian border on Tuesday.

"We were really scared. We left Kyiv last Friday. It took us so long to get here," Laura Kusnirova, 54, told AFP after getting off a train.

Relief groups have set up stalls with food, water and other aid supplies in train stations in Budapest
Relief groups have set up stalls with food, water and other aid supplies in train stations in Budapest AFP / FERENC ISZA

Carrying a little dog in a shoulder bag, she said tearfully "how could I leave her behind," before rushing off.

Like Kusnirova, who is planning to head to Brussels to stay with friends, relief organisations say most of the refugees plan to travel onwards rather than stay in Hungary.

Around 4,000 refugees, including more than 300 children, arrived by train in Budapest on Monday, according to police, and hundreds were provided with emergency accommodation in the city.

Around 4,000 refugees, including more than 300 children, arrived by train in Budapest on Monday, police said
Around 4,000 refugees, including more than 300 children, arrived by train in Budapest on Monday, police said AFP / FERENC ISZA

Relief groups have set up stalls with food, water and other aid supplies in train stations in Budapest, said Marton Juhasz, head of the Hungarian Reformed Church's charity.

"Some just need baggage storage or onward travel information, but others are in urgent need of food, water and shelter, even psychological help as many have left family behind," Juhasz told AFP while waiting for the next train to arrive.

Svetlana Hogert, a volunteer translator originally from western Ukraine where a large ethnic-Hungarian minority lives, said many people in her home country were frightened.

"I came here to help in any way I can," the 46-year-old, who has lived in Hungary for years, told AFP.

Since Russia invaded Ukraine last week, volunteers have rushed to the aid of refugees entering Hungary, which in past years has restricted asylum seekers' access under nationalist Prime Minister Viktor Orban.

More than 660,000 people have already left Ukraine and an estimated one million are displaced within the country, the UN refugee agency says.

The United Nations estimated on Monday that some 90,000 people from Ukraine had arrived in EU member Hungary since last week.