A Russian drone strike on the Ukrainian city of Dnipro hit a bus carrying mineworkers and killed at least 15 people.
Hours earlier, a Russian strike hit a maternity hospital in southern Ukraine on Sunday injuring six people.
The attacks come after Ukrainian President Volodymyr Zelenskyy announced the next round of peace talks between Russian and Ukrainian delegations will take place on Wednesday and Thursday.
Ukrainian emergency services said a Russian drone strike on the Ukrainian city of Dnipro hit a bus carrying mineworkers and killed 15 people on Sunday.
The strike injured a further seven people and sparked a fire that was subsequently put out.
DTEK, Ukraine's largest private energy company, said it owned the bus and accused Russia of carrying out "a large-scale terrorist attack on DTEK mines in the Dnipropetrovsk region," whose capital is Dnipro.
The company said "the epicentre of one of the attacks was a company bus transporting miners from the enterprise after a shift in the Dnipropetrovsk region."
Hours earlier, a Russian strike hit a maternity hospital in southern Ukraine on Sunday injuring six people.
The Zaporizhzhia administration said the hospital was hit around midday causing damage to the building.
The strike sparked a fire in the gynaecology reception area that was later extinguished.
According to the Ukrainian State Emergency Service the attack also damaged homes in Zaporizhzhia, injuring three people.
Meanwhile, Ukrainian President Volodymyr Zelenskyy confirmed trilateral talks between Ukraine, the United States, and Russia will take place on Wednesday and Thursday in the United Arab Emirates.
Zelenskyy said he had scheduled a meeting to agree on the framework of the conversation and prepare everything.
Zelenskyy added the team would be on their way to the Emirates on Monday evening.
The Ukrainian president noted he expected that the American side "will be just as active", and "in particular this concerns de-escalation measures - reducing strikes".
Commenting on the Russian strikes, he said they "demonstrate Moscow is responsible for the escalation in the conflict with Ukraine."