<div><span style="font-size: 1rem;">Ukraine's president has condemned a Russian strike that the region's governor said killed at least six people and wounded 16 in Ukraine's Kharkiv on Wednesday as "despicable and cynical".</span><br></div><div><br></div><div>President Volodymyr Zelensky said a block of flats was "totally destroyed" in the attack, which he said "had no justification and shows the powerlessness of the aggressor".</div><div><br></div><div>"We will not forgive, we will take revenge", the president said on the Telegram app.</div><div><br></div><div>The strike started a fire in a block of flats in the northeastern city, mayor Igor Terekhov said on Telegram.</div><div><br></div><div>He earlier gave a toll of three dead and ten wounded, but regional governor Oleg Synegubov said the numbers had risen.</div><div><br></div><div>"Unfortunately the number of deaths and injuries following the bombardment... has increased: six people died and 16 were wounded," Synegubov said on Telegram.</div><div><br></div><div>Kharkiv was besieged in the first days of the invasion in February.</div><div><br></div><div>But Russian troops -- backed by massive artillery fire and missile strikes -- have not been able to take control of Ukraine's second city.</div><div><br></div><div>Hundreds of people have been killed in the region, authorities say.</div><div>On Monday, Russian shelling in the city killed at least one person and injured six more, senior police official Sergiy Bolvinov said on Facebook.</div><div><br></div><div>The bulk of Russia's offensive is now focussed on southern and eastern Ukraine. - AFP&nbsp;</div><div><br></div><div>bnbd24/fas</div>