Russia took aim at Western military supplies for Ukraine at the weekend, launching airstrikes on Kyiv that it claimed destroyed tanks donated from abroad, as Vladimir Putin warned that any Western deliveries of longer-range rocket systems would prompt Moscow to hit "objects that we haven't yet struck". 

The Russian leader's cryptic threat of military escalation did not specify what the new targets might be. 

It came days after the United States announced plans to deliver US$700 million of security assistance for Ukraine that includes four precision-guided, medium-range rocket systems, as well as helicopters, Javelin anti-tank systems, radars, tactical vehicles and more. 

Military analysts say Russia hopes to overrun Ukraine's embattled eastern industrial Donbas region, where Russia-backed separatists have fought the Ukrainian government since 2014, before any US weapons that might turn the tide arrive. 

Protester holds a Stop Putin banner during a demonstration against the Russian invasion of Ukraine. Photo / AP 

The Pentagon said last week that it will take at least three weeks to get the US weapons onto the battlefield. 

Ukraine said the missiles aimed at the capital hit a train repair shop. 

Elsewhere, Russian airstrikes in the eastern city of Druzhkivka destroyed buildings and left at least one person dead, a Ukrainian official said. Residents described waking to the sound of missile strikes, with rubble and glass falling down around them. 

"It was like in a horror movie," Svitlana Romashkina said. 

Donetsk Governor Pavlo Kyrylenko urged city residents to leave, saying on Facebook that ruined buildings can be restored but "we won't be able to bring back the lives lost". 

The Russian Defence Ministry said air-launched precision missiles were used to destroy workshops in the Donetsk region of eastern Ukraine, including in Druzhkivka, that were repairing damaged Ukrainian military equipment. 

Meanwhile, Ukraine's General Staff said Russian forces fired five X-22 cruise missiles from the Caspian Sea toward Kyiv, and one was destroyed by air defences. 

Four other missiles hit "infrastructure facilities" but Ukraine said there were no casualties. Nuclear plant operator Energoatom said one cruise missile buzzed close to the Pivdennoukrainsk nuclear plant, 350km to the south, and warned of the possibility of a nuclear catastrophe if even one missile fragment hit the plant. 

On the Telegram app, the Russian Defence Ministry said high-precision, long-range air-launched missiles were used on the outskirts of Kyiv, destroying T-72 tanks supplied by Eastern European countries and other armoured vehicles in a train car repair shop. 

But the head of Ukraine's railway system rejected the claim that tanks were inside. Oleksandr Kamyshin said four missiles hit the Darnytsia car repair plant, but no military equipment has been stored there. 

He said the site was used to repair gondolas and carriers for exporting grain. "Russia has once again lied," he wrote on Telegram. "Their real goal is the economy and the civilian population. They want to block our ability to export Ukrainian products." 

In a television interview that aired Sunday, Putin lashed out at Western deliveries of weapons to Ukraine, saying they aim to prolong the conflict. 

"All this fuss around additional deliveries of weapons, in my opinion, has only one goal: to drag out the armed conflict as much as possible," Putin said. He insisted such supplies were unlikely to change the military situation for Ukraine's government, which he said was merely making up for losses of similar rockets. 

If Kyiv gets longer-range rockets, he added, Moscow will "draw appropriate conclusions and use our means of destruction, which we have plenty of, in order to strike at those objects that we haven't yet struck". 

The US has stopped short of offering Ukraine longer-range weapons that could fire deep into Russia. But the four medium-range High Mobility Artillery Rocket Systems in the security package include launchers on wheels that allow troops to strike a target and then quickly move away — which could be useful against Russian artillery on the battlefield. 

The Spanish daily El Pais has reported that Spain planned to supply anti-aircraft missiles and up to 40 Leopard 2 A4 battle tanks to Ukraine. Spain's Ministry of Defence did not comment on the report. 

In Kyiv's eastern Darnystki district, a pillar of smoke filled the air with an acrid odour over the charred, blackened wreckage of a warehouse-type structure. Soldiers blocked off a nearby road leading toward a large railway yard. 

A street damaged by shelling in Mariupol, Ukraine. Photo / AP 

Before the weekend's attack, Kyiv had not faced any such Russian airstrikes since the April 28 visit of UN Secretary-General António Guterres. The attack triggered air-raid alarms and showed that Russia still had the capability and willingness to hit at Ukraine's heart, despite refocusing its efforts to capture Ukrainian territory in the east. 

In recent days, Russian forces have focused on capturing Ukraine's eastern cities of Sievierodonetsk and Lysychansk. Their push included missile and airstrikes on cities and villages in the Donbas. 

In the cities of Sloviansk and Bakhmut, cars and military vehicles were seen speeding into town from the direction of the front line. Dozens of military doctors and paramedic ambulances worked to evacuate civilians and Ukrainian servicemen, and a hospital was busy treating the injured, many hurt by artillery shelling.