An overnight Russia drone attack has left Ukraine's western city of Ternopil without electricity, a regional military official said on Tuesday, a week after Moscow's strikes cut power to much of the city and its surrounding region.

"Energy workers and rescuers are eliminating the consequences of the attack. Stock up on water, charge your phones," Serhiy Nadal, the head of the regional defence headquarters in Ternopil, said on his Telegram messaging channel.

The full scale of the attack on Ternopil, a major city in Ukraine's west, was not immediately clear. Air raid alerts over the Ternopil region, of which the city of Ternopil is the administrative centre, lasted for about 2-1/2 hours, starting at around 2330 GMT on Monday.

One person was killed and several were wounded in Russia's drone attack on Ternopil earlier on Monday.

A week ago, much of the Ternopil region lost power in Russia's largest ever drone attack on Ukraine.

Ternopil, some 220 km (135 miles) east of NATO-member Poland, and the surrounding region had a population of more than 1 million before the February 2022 Russian invasion, which drove many Ukrainians west.