Russian strikes on Ukraine's second-largest city Kharkiv killed at least seven people, authorities said Thursday, as Moscow claimed fresh advances on the front line.

The surrounding region of Kharkiv has become the latest flashpoint of the war after Russian forces launched a surprise ground offensive in the northeast border territory this month, forcing the evacuation of thousands of residents.

The barrage of more than a dozen projectiles came as Moscow said it captured Andriivka in the industrial Donetsk region, one of the few villages Ukraine wrested back in its lacklustre counteroffensive last summer.

Kyiv's forces are suffering manpower and ammunition shortages and struggling to hold off Russian attacks.

Emergency workers were clearing debris, extinguishing flames and retrieving victims from the rubble in the aftermath of the latest attack on Kharkiv, images distributed by Ukrainian officials showed.

President Volodymyr Zelensky described the barrage as "brutal" and said Russia was "taking advantage" of Ukraine's lack of air defence systems to launch fatal attacks on towns and cities at his country's border.

The regional governor said seven people had been killed and that another 16 were wounded.

Ukraine's national railway operator said civilian railway infrastructure had been hit in Kharkiv and the surrounding region in the aerial assault and that six employees had been wounded.

Regional authorities said a printing press had also been damaged.

- Ukraine 'lacks' air defences -

Kharkiv, which is the second-largest city in Ukraine and lies just dozens of kilometres from the border with Russia, has been under persistent shelling since Moscow's forces invaded in February 2022.

"Russian terrorists are taking advantage of the fact that Ukraine still lacks sufficient air defence protection," Zelensky said on social media.

Ukrainian officials have been urging allies to send more air defences and this week suggested that Kyiv's neighbours shoot down Russian missiles using systems deployed in their own countries.

Foreign Minister Dmytro Kuleba again called on Ukraine's Western partners to send seven Patriot systems, saying "they are needed now, not tomorrow."

"No naming and shaming, but I once again urge countries that have Patriots to speed up decisions and provide these systems to Ukraine," Kuleba added in a social media post.

Separately, the head of Ukraine's Zaporizhzhia region, which the Kremlin claims is part of Russian territory, said a 74-year-old man was killed by Russian shelling on the village of Mala Tokmachka.

Russian forces have in recent weeks made their biggest territorial gains in a year in the war-battered east as Ukraine waits for desperately needed US and European weapon supplies.

The defence ministry in Moscow said on Thursday it had recaptured the village of Andriivka in the eastern Donetsk region.

The advances in Kharkiv have forced nearly 11,000 people to flee their homes since Moscow launched its ground assault on May 10, regional officials meanwhile said.

Russian authorities meanwhile said that Ukrainian attacks on the border region of Belgorod and in the occupied Ukrainian region of Donetsk left two dead.

Russian President Vladimir Putin said his army launched the offensive in Kharkiv to create a buffer zone that would protect Russian border villages from Ukrainian attacks.