Ukraine war: Putin claims 'invincibility', UK arms giant in Ukraine, new drone strikes in Russia

Russia is as "invincible" today as it was during the Second World War, Vladimir Putin said on Friday during a meeting with teenagers to mark the start of the new school year.

"I understood why we won the Great Patriotic War: it's impossible to defeat a people with that kind of mindset. We were absolutely invincible and, today, we still are", said the Russian president, in remarks broadcast on television.

Putin regularly draws parallels between the war against Nazi Germany and the offensive he has unleashed in Ukraine.

Russia claimed on Friday to have seized "key positions on high ground" near the town of Kupiansk in eastern Ukraine, a sector of the front on which its troops have been on the offensive for several weeks.

Russia has deployed major resources to regain control of the Kupiansk sector, which was recaptured by Ukraine last year, and according to Ilia Yevlach, spokesman for the Ukrainian army's Eastern Command, 45,000 of its soldiers are massed there.

Ukrainian forces targeted Russia's Kursk region with two drones early on Friday, damaging residential and administrative buildings, local authorities said. 

Two buildings were damaged, which emergency services were still assessing, the region's governor Roman Starovoit wrote on Telegram. 

Russian forces downed another drone bound for Moscow on Friday morning, the capital's mayor Sergei Sobyanin said. 

The drone was shot down just 20 kilometres southeast of central Moscow, Sobyanin wrote on Telegram, without disclosing further details. 

Moscow's three major airports had to reschedule and cancel flights after an unidentified flying object was detected by air defences, the Russian state-run news agency TASS reported.  

Sobyanin has been vocal about expanding the Russian