At least 22 killed in Russian strike on rail station on Ukraine’s independence day

At least 22 people have been killed and 50 wounded in a Russian rocket strike on a Ukrainian railway station, as the country marked six months since Moscow's invasion on a sombre independence day overshadowed by warnings of further "brutal" attacks.

Addressing the UN late on Wednesday, Ukraine's president, Volodymyr Zelenskiy, said the rockets struck a train in a station in the town of Chaplyne, about 145km (90 miles) west of Donetsk in eastern Ukraine.

"Rescuers are working, but, unfortunately, the death toll could increase," Zelenskiy said.

An 11-year-old child died in the attack, said Kirill Timoshenko, deputy head of Ukraine's presidential administration, in a message on his Telegram channel.

Ukraine had been bracing for especially heavy attacks around the national holiday that commemorates its declaration of independence from the Soviet Union in 1991.

Earlier in the day, air raid sirens had sounded across every metre of Ukrainian-controlled territory. The sense of foreboding was deepened by a warning from the White House that the Russians had stepped up preparations to hold sham referendums in occupied regions as a precursor to annexations, and that they could begin "in a matter of days or weeks".

Joe Biden announced a further $3bn (£2.5bn) in military aid, including anti-aircraft missiles, artillery, counter-drone defences and radar equipment, as a show of US support on Ukrainian independence day, while senior politicians from across Europe travelled to Kyiv to show their support in person, despite security warnings including a US call for its citizens to leave the country.

The UK prime minister, Boris Johnson, in his third visit to the country since Russia invaded, urged the international community to "stay the course" in its support for Ukraine. He also told Zelenskiy that Ukraine "can and will win the war".

It is 31 years since Ukraine declared its independence from the Soviet Union, and six months to the day since Russia launched a war aiming to reverse that step away from Moscow's control.

Many in the capital on Wednesday were taking stock of both their achievements and losses. Few outside Ukraine, even among its allies, expected the country to hold off Russia's army so effectively, including in a decisive victory outside Kyiv.

But the country has paid a terrible human price for its success so far. Thousands of civilians have been killed since the war began on 24 February, while Ukraine has acknowledged 9,000 military deaths, millions have lost their homes or been forced into exile, and there is little hope that an end to the fighting is in sight.

"I'm constantly worried and praying that our skies remain blue and I understand that people are giving their lives for this," said Yana Pasychnyk, a choral singer in one of Ukraine's national choirs. She was heading home after performing at Kyiv's St Sophia Cathedral.

"As I'm speaking to you now I have goosebumps. People I know, my godson even, is fighting at the front. There's no celebration today. I can't even believe that this is happening."

Earlier, Zelenskiy told his fellow citizens that their country was reborn when Russia invaded, in a speech recorded on the steps of the capital's monument to independence.

"A new nation appeared in the world on 24 February at four in the morning. It was not born, but reborn. A nation that did not cry, scream or take fright. One that did not flee. Did not give up. And did not forget," he said.

He pledged to keep fighting until Ukraine had recaptured annexed Crimea and occupied areas in the east. "What for us is the end of the war? We used to say peace. Now we say victory."

A spokesperson for Biden's national security council, John Kirby, warned that Moscow was making preparations to stage referendums in the occupied areas.

"We have information that Russia continues to prepare to hold these sham referendum in Kherson, Zaporizhzhia, and the so called Donetsk and Luhansk people's republics," Kirby said. "We've also learned that the Russian leadership has instructed officials to begin preparing to hold sham referenda, particularly in Kharkiv as well. And these referenda could begin in a matter of days or weeks. In fact, we can see a Russian announcement of the first one or ones before the end of this week."

Kirby said that holding referendums, intended as a prelude to annexation, was proving a challenge to Russian organisers in the face of the near-total opposition of Ukraine's population.

Meanwhile, the Russian defence minister, Sergei Shoigu, claimed that the slowing pace of Russia's military campaign in Ukraine was deliberate, and driven by the need to reduce civilian casualties.

Shoigu said: "Everything is being done to avoid casualties among civilians. Of course, this slows down the pace of the offensive, but we are doing this deliberately."

Zelenskiy had warned on the eve of the holiday that Ukraine might face "repugnant Russian provocations", and urged citizens to take seriously any air raid warnings - often ignored by a population now inured to the risks of war.

Zelenskiy also celebrated national unity, which has been bolstered by a powerful government messaging campaign. "We are fighting against the most terrible threat to our statehood and also at a time when we have achieved the greatest level of national unity," he said.

A display of destroyed Russian tanks and other military equipment on the main street of the capital replaced the usual military parade through the centre of Kyiv, cancelled over fears that such a symbolic day could attract fresh attacks.

It was both a celebration of Ukraine's military success and a trolling of Moscow's expectations of a quick victory; it had sent some soldiers to battle with parade uniforms that they had expected to use in Kyiv.