Kiev, June 15 : Ukraine's Deputy Defence Minister Hanna Maliar has confirmed that "extremely fierce battles" are raging in parts of the country as forces continue their counter-offensive against Russia. In a social media post late Wednesday, Maliar said that Ukrainian troops had advanced around the key city of Bakhmut, which has for months been at the heart of fierce fighting, reports the BBC. She said soldiers advanced by 200m to 500m towards the city, as well as advancing 300m to 500m in the southern Zaporizhzhia province. But Maliar also conceded that the counter-offensive had already led to some "extremely fierce battles", as Ukrainian forces try to break through well established Russian defensive lines. Since Ukraine launched its much-anticipated counter-offensive on June 10, officials said seven settlements and at least 90 sq km of land have been recaptured. The Deputy Defence Minister's claims come as Russia has stepped up its bombing campaign in recent weeks, despite President Vladimir Putin admitting that his forces are suffering from a shortage of missiles and drones. The latest wave included a relatively rare strike on the Black Sea port city of Odesa on Wednesday, which killed three people and injured 13 others. In his nightly address to the nation on Wednesday, President Volodymyr Zelensky thanked "everyone who is currently fighting in the east and south of our country, opening up strategic space for Ukraine, space for movement to victory". "I thank all those who are now on the offensive and on the defensive, who are storming the occupiers' positions and repelling their attacks." /IANS