Russia has claimed strikes on hundreds of targets across Ukraine in what appeared to be an intensified bid to grind down the country’s defences ahead of an all-out assault on the eastern region.

It also directed missiles at Kharkiv and the safe-haven city of Lviv, where casualties were recorded the first time since the start of the invasion.

Andriy Yermack, the chief of staff to Ukraine’s president, warned: “The second phase of the war has started”.

Meanwhile, Russian President Vladimir Putin has bestowed military honours on the countrymen who have been accused of massacring civilians in the city of Bucha.

Here’s what you need to know about the latest onslaught in Ukraine.

‘No longer anywhere safe’

The mayor of Lviv has called on residents to take shelter when sirens sound, as the city will almost certainly face further attacks from Russian forces.

“I reiterate my call to all the residents: Whenever you hear a siren, please, we mourn the fallen but we have to be vigilant because the enemy is getting more and more atrocious,” Andriy Sadovyi said.

“You have to protect yourselves.”

At least seven people were reported killed in that city, which has seen only sporadic attacks and has been a haven for civilians fleeing the fighting elsewhere.

A hotel there sheltering elderly Ukrainians, mothers and children was among the buildings badly damaged, Mr Sadovyi said.

“The nightmare of war has caught up with us even in Lviv,” said Lyudmila Turchak, who has been sheltering with her small children in Lviv since fleeing from Kharkiv.

“There is no longer anywhere in Ukraine where we can feel safe.”

Lviv – the biggest city and a major transportation hub in western Ukraine – is about 80 kilometres from Poland, a NATO member.

To the Kremlin’s increasing anger, Lviv has also become a major conduit for NATO-supplied weapons and foreign fighters joining the Ukrainian cause.

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Russia has strongly complained about the increasing flow of Western weapons to Ukraine. On Russian state media, some anchors have charged that the supplies amount to direct Western engagement in the fight.

Russia’s Defense Ministry said its missiles destroyed the 124th Joint Logistics Support Center in the Lviv area.

The New York Times reported that Russia claimed “large-scale shipments of foreign weapons” had been stored in the warehouses, a claim that could not immediately be confirmed.

Ukrainian officials said the warehouses were empty.

The strikes also hit an auto mechanic shop, according to the region’s governor, Maksym Kozytskyy. He said the wounded included a child.

A powerful explosion also rocked Vasylkiv, a town south of the capital of Kyiv that is home to a military air base, according to residents. It was not immediately clear what was hit.

More civilian casualties amid ‘softening-up’ campaign

The BBC reports that Ukraine’s National Security Council Secretary Oleksiy Danilov said Russia has attempted to break through defences “along almost the entire front line of Donetsk, Luhansk and Kharkiv regions”.

“They began their attempt to start the active phase,” Mr Danilov added.

Kharkiv, Ukraine’s second-largest city, was hit by shelling that killed at least three people, according to Associated Press journalists on the scene.

One of the dead was a woman who appeared to be going out to collect water in the rain. She was found lying with a water canister and an umbrella by her side.

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Military analysts say Russia is increasing its strikes on weapons factories, railways and other infrastructure targets across Ukraine to wear down the country’s ability to resist a major ground offensive in the Donbas, Ukraine’s mostly Russian-speaking eastern industrial heartland.

General Richard Dannatt, a former head of the British Army, told Sky News that Russia is waging a “softening-up” campaign ahead of the offensive in the Donbas, whose capture has become the Kremlin’s main goal since its attempt to storm Kyiv failed.

Honours for soldiers behind Bucha atrocities

Russia’s 64th Detached Motor Rifle Brigade is accused of massacring civilians in the city of Bucha.

But their president has hailed them heroes and granted the brigade the honorary title of Guard.

“For its heroism and courage for the strength and merits shown by the brigade in combat to defend the Homeland and the interests of the State in conditions of armed conflict, I decree (…) assign the honorary title of Guard to the 64th Guards Detached Motor Rifle Brigade,” a presidential decree said.

• Related: ‘Butcher of Bucha’ is decorated soldier

After the withdrawal of Russian troops from northern Kyiv, Ukrainian authorities denounced a massacre of civilians in Bucha, where several hundred bodies were found, some of whom were handcuffed.

The Ukrainian military intelligence released on its website the personal data of 1600 Russian soldiers belonging to that brigade, whom Kyiv has blamed for the alleged massacre.

The Kremlin rejected the accusations as false, and demanded that Western leaders not rush into making “gratuitous accusations”.

-with AAP