Poland and other countries prepare to receive fleeing Ukrainians

The countries on the European Union's eastern flank were all once part of the Moscow-led Warsaw Pact and are now members of NATO. Among them, Poland, Hungary, Slovakia and Romania all share land borders with Ukraine.

Earlier on Thursday, Russia launched an all-out invasion of Ukraine by land, air and sea, the biggest attack by one state against another in Europe since World War Two. It confirmed the worst fears of the West and prompted fears of a huge flood of refugees fleeing Ukraine, a nation of 44 million people.

Poland called for the "fiercest possible sanctions" against Russia and the Czech foreign minister called it a "barbaric act of aggression".

By early Thursday Hungary, which has forged good ties with President Vladimir Putin's Russia, had not explicitly condemned the attack, but its foreign minister said war was "the worst-case scenario". He reiterated that Hungary fully supported Ukraine's sovereignty and territorial integrity.

"In the next few hours, reception points for refugees from Ukraine will be created," the PAP news agency quoted Polish Deputy Minister of Internal Affairs Pawel Szefernaker as saying.

Eight such points will be created near the border in the first stage, to provide food, medical assistance and information for potential refugees, he said.

Hungary has said it will send an unspecified number of troops to the border area with Ukraine for security and humanitarian reasons, though there was no sign of any deployment on Thursday morning. 

A Polish goverment spokesman said Polish diplomatic missions in Ukraine would remain open "as long as possible" but the foreign ministry urged all Polish citizens to leave Ukraine.

Hungary also said its embassy in Kyiv remained open but the Czech Republic closed its diplomatic mission, though its consulate in the west Ukrainian city of Lviv remained open.

The Slovak railway halted services to Ukraine, and budget airline Wizz temporarily suspended all flights in and out of Ukraine. 

A Reuters reporter at Hungary's main border crossing of Zahony to Ukraine said the border was quiet, with trucks lining up to enter as usual in the foggy cold.

Hungary must prepare to receive tens of thousands of refugees if necessary, Defence Minister Tibor Benko told commercial ATV late on Wednesday.

Budapest must also prepare for the possibility that soldiers engaged in combat could "drift over" the border, as happened during the Yugoslav wars of the 1990s, he added, without elaborating.

Ukraine's western borders were relatively quiet on Thursday morning but officials and witnesses said traffic has picked up slightly.

"We can see moderately higher traffic at border crossings with Ukraine, we assume it will grow during the day," a Slovak interior ministry official said.

"Slovakia is ready to help, we could allow in people who don't have all the necessary documents on them."

Ukraine's ambassador to Prague, Perebyjnis Jevhen, told a news conference: "I cannot exclude some waves of people. But it will rather be to the western part of Ukraine than abroad."

There are around 260,000 Ukrainians living in the Czech Republic, and tens of thousands working in Hungary, which has a large ethnic minority of around 140,000 living in Ukraine just beyond the border.

Bulgarian President Rumen Radev said his country was preparing to evacuate by land more than 4,000 ethnic Bulgarians from Ukraine and was ready to host other Ukrainian refugees.

Bulgarian Prime Minister Kiril Petkov said the Balkan country would prepare hotels and other tourism bases to host them. Bulgaria has no land border with Ukraine but is a Black Sea littoral state, as are both Ukraine and Russia.