Russia has increasingly focused its strikes on the capital Kyiv. Kyiv has been targeted in 17 out of 21 reported Russian attacks on Ukraine in May, compared with twice out of seven attacks in April.

Russia said on Thursday it had repelled more cross-border attacks from Ukraine while its aerial assaults on Kyiv killed another three people including a nine-year-old girl and her mother locked out of an air raid shelter.

Explosions rattled Kyiv during daylight Monday as Russian ballistic missiles took aim at the Ukrainian capital.

Russia said on Monday its military hit Ukrainian air bases in overnight strikes and Ukrainian forces shelled industrial facilities inside Russia as both sides sought the upper hand ahead of what Kyiv hopes will be a decisive counter-offensive.

On Monday, explosions shook the city in a rare daylight attack. Valerii Zaluzhnyi, the commander-in-chief of Ukraine's Armed Forces, said Russian forces fired 11 ballistic and cruise missiles at Kyiv at about 11:30 a.m. local time, with air defense systems shooting all of them down.

Russia fired missiles and drones at targets across Ukraine in the early hours of Saturday, killing three civilians in the Black Sea city of Odesa and striking a military air field in the central Poltava region,