Ukrainian forces enter Russia's Kursk region; Putin calls it a "major provocation"

Ukrainian units have been fighting on the territory of Russia's Kursk region for a second day. The Russian Defence Ministry reports repelling attacks near Sudzha.

Kursk Governor Alexei Smirnov declared a state of emergency in the region. Thousands of residents have been evacuated from border districts.

President Vladimir Putin called the events "another large-scale provocation". It is the largest operation by foreign troops on Russian territory since the Second World War.

The Ukrainian authorities have made almost no official comment on the operation.