(Reuters) - Russian shelling killed at least one civilian and injured two more in Ukraine's Sumy region, the local administration said, as Kyiv troops proceed with their major cross-border assault in Russia's adjacent Kursk region.

The casualties were reported in the Krasnopillia area, the regional military administration said.

It said 45 Russian attacks on the region had been recorded on Tuesday, including guided bomb strikes, explosions from drones, and shelling.

The regional military said Russia stepped up airstrikes on border settlements following the incursion.

Kyiv's military on Tuesday restricted the movement of civilians within a 20 km (12 mile) zone of the northeastern border area.

It cited an "increase in the intensity of hostilities" and the activation of Russian sabotage and reconnaissance groups, adding the measure was temporary and that residents could still access their homes by showing proof of registration.

(Reporting by Yuliia Dysa; editing by Jonathan Oatis)