"The Secretary-General remains deeply concerned about the rising toll on civilians and the destruction of critical civilian infrastructure, including energy facilities and ports, from the ongoing attacks in Ukraine, as well as in the Russian Federation," the spokesman said.
He added that the UN was unable to verify any details "due to lack of access."
"Attacks on civilians and civilian infrastructure are prohibited under international law. No matter where they occur, they are unacceptable and must stop," Dujarric said.
Guterres also called for a ceasefire in Ukraine, he said.
Ukrainian forces carried out a drone strike on a cafe and hotel in the Kherson Region during New Year celebrations overnight Wednesday to Thursday, according to regional Governor Vladimir Saldo. Preliminary data showed that 27 people, including two minors, were killed and over 50 injured. The Russian Investigative Committee has opened a terrorism case regarding the deaths of more than 20 civilians.