Russian forces are continuing their attacks on the southern Ukrainian region of Odesa.

Ukrainian officials said on Sunday that at least one person was killed and 22 others, including children, were wounded in overnight missile strikes on the port city of Odesa.

They also said residential buildings were destroyed and a cathedral was severely damaged.

Ukrainian forces said Russian troops targeted the Odesa region with at least five types of missiles. They included Kalibr cruise missiles and the short-range Iskander-M.

In a social media post on Sunday, Ukraine's President Volodymyr Zelenskyy said, "There can be no excuse for Russian evil." He went on to say, "There will definitely be a retaliation to Russian terrorists for Odesa."

A US think tank said on Saturday that Ukraine has reported the presence of fighters from the private Russian military firm Wagner Group at several training grounds in Belarus.

The Institute for the Study of War noted that "The Wagner Group's footprint in Belarus is likely expanding."

Wagner fighters staged a short-lived armed rebellion against Moscow last month.