Russia has imposed a “counter-terrorism operation” regime in three regions to try to halt a surprise cross-border incursion by Ukrainian troops.

The authorities in the Kursk, Belgorod and Bryansk regions on the border with Ukraine now can restrict the movement of people and vehicles and use phone tapping among other measures.

This comes as the Ukrainian offensive into the Kursk region is now in its fifth day. Kyiv has not openly admitted the incursion.