Russia is sending more forces to its Kursk region in an attempt to repel a Ukrainian attack that is now in its fourth day.
Russian state media say Moscow is deploying multiple rocket launchers, artillery guns, and heavy tanks to fend off one of Ukraine's biggest incursions into Russian territory since the war began.
The attack has prompted Russia to declare a regional state of emergency.
This video obtained by Reuters news agency allegedly shows a destroyed Russian military convoy in the Kursk region.
According to Russian estimates, around one thousand Ukrainian troops and more than two dozen armoured vehicles and tanks were involved in the initial attack.