Protests against Russian occupation have broken out in the port city of Kherson, Ukraine’s only big city to have been captured in the war so far.
About 2,000 people marched through the city centre, waving flags and singing the Ukrainian national anthem.
They shouted patriotic slogans including “Russians go home” and “Kherson is Ukraine”.
Kherson, a key port on the Black Sea and the Dnieper River, fell to Russian troops earlier this week.
Elsewhere in the country on the 10th day of the invasion, the Russian defence ministry said its units had opened humanitarian corridors to let civilians leave the cities of Mariupol and Volnovakha, which are under siege by its forces.
However, Ukrainian authorities said Russia was not observing the ceasefire and attacks were continuing, so mass evacuations had been postponed.
Russia later announced that its assault on Mariupol was under way again.
“Due to the unwillingness of the Ukrainian side to influence nationalists or extend the ceasefire, offensive actions have been resumed,” a Russian defence ministry spokesman said.
Mariupol, a port city of about 400,000 people, is a key strategic target for Russia because seizing it would allow Russian-backed separatist forces in eastern Ukraine to join forces with troops in Crimea, the southern peninsula annexed by Russia in 2014.