Russia announced a ceasefire for Friday and Saturday when it commemorates the Soviet Union victory over Nazi Germany in World War II and holds a military parade.
Ukraine, in response, announced a proposal for an open-ended ceasefire starting at midnight on Wednesday, urging Russia to reciprocate.
President Volodymyr Zelenskiy said it was not an option for Russia to halt strikes for one day for its military parade after heavily pounded Ukraine.
In the southeastern city of Zaporizhzhia, an attack by aerial bombs and drones killed at least 12 people and injured 20, Regional Governor Ivan Fedorov said on Telegram.
Residential buildings, a car repair service and a car wash were damaged. The attack also sparked fires at a shop and an unidentified enterprise, he added.
Images from the site that he shared showed a heavily damaged building with billowing flames and smoke.
Cars are seen burning as first responders help bloodied people leave the site.
Three aerial bombs dropped on the eastern frontline city of Kramatorsk, killing five other people, Zelenskiy said on Telegram.
Five people were injured, he added, warning that the death toll might rise.
Ukrainian Foreign Minister Andrii Sybiha, writing on X, said: "With mere hours until Ukraine's ceasefire proposal comes into force, Russia shows no signs of preparing to end hostilities. On the contrary, Moscow intensifies terror".
A Russian overnight strike on the gas production facilities in the Poltava region killed five, Ukrainian officials said.
Ukraine's government made clear on Tuesday that it was prepared to extend indefinitely a ceasefire due to go into effect at midnight.
"If the ceasefire announced by the President (Volodymyr Zelenskiy) is reciprocated, we will continue to observe it. And this will give us at least a small glimmer of hope for achieving a lasting peace," presidential office head Kyrylo Budanov posted on social networks.
"The next move is Russia's," he said.
"We are closely monitoring every move by the enemy and are prepared for any possible developments," he added.
In Dnipro, also in southeastern Ukraine, a Russian attack killed four, Zelenskiy said.
"These are absolutely cynical, senseless terrorist strikes void of any military sense," Zelenskiy wrote on Telegram. "Such Russian strikes on our cities and villages do not cease for a single day."
In Russia, a Ukrainian drone attack on the Chuvashia region killed two on Tuesday, the Russian state news agency reported.
Russia's vast Kirishinefteorgsintez (Kirishi) oil refinery halted processing on Tuesday following Ukrainian drone attacks which damaged the plant's units and caused a fire, two industry sources said.
Officials in Russian-held Crimea said air defence units had repelled an attack by Ukrainian drones. Russia's Defence Ministry said air defence units had intercepted 93 Ukrainian drones over Crimea and several regions in southern and central Russia.
with DPA
