A Russian soldier walked through a Ukrainian crowd holding what appeared to be two grenades in the air, jeered by angry onlookers.
He was thought to be part of a Russian delegation sent to the city of Konotop in northeastern Ukraine to call on residents to surrender.
Another soldier followed him, his hands in the air.
The pair were followed by furious shouts from Ukrainians, some people jostling them, and their vehicle tyres were reportedly punctured.
The troops threatened to raze the city with artillery strikes, according to Artem Semenikhin, mayor of Konotop, which has about 86,000 inhabitants.
He told residents in a public address in the street that the Russians had surrounded the city and delivered an ultimatum - either he surrender the city to them or they would completely destroy it.
Asking people whether they should fight or surrender, the crowd overwhelmingly responded that they backed fighting.
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Russia’s invasion of Ukraine entered its second week on Thursday with its main assault force halted north of the capital Kyiv and several cities enduring heavy Russian bombing.
Ukrainian president Volodymyr Zelensky has said his country’s armed forces are holding off the Russian advance.
But Russia claims to have taken “complete control” of the Black Sea port of Kherson.
Ukraine fears Russia may be preparing to stage a so-called false flag operation near the Ukraine-Russia border to suggest Ukraine has attacked a Russian village, Ukrainian Foreign Minister Dmytro Kuleba says.
In Ukraine’s Chernihiv region, at least nine people have been killed and four wounded after a Russian air strike hit two schools and private houses on Thursday, governor Viacheslav Chaus said.
Heavy fighting has continued on the outskirts of Mariupol, a strategic port city on the Azov Sea, plunging it into darkness, isolation and fear. Electricity and phone connections are largely down, and homes and shops are facing food and water shortages.
