Russian forces staged their largest ever drone attack on Ukraine overnight, cutting power to much of the western region of Ternopil and damaging residential buildings in Kyiv region, Ukraine's officials said yesterday.

Intensified nightly drone attacks on Ukrainian cities are coinciding with a major push by Russia along frontlines in Ukraine's east, where Russian forces have made some of the largest monthly territorial gains since 2022.

Of 188 drones used overnight, Ukraine shot down 76 and lost track of 96, likely due to active electronic warfare, the air force said. Five drones headed towards Belarus.

"The enemy launched a record number of Shahed attack UAVs and unidentified drones ...," it said, in addition to using four Iskander-M ballistic missiles. Russia uses cheaply-produced "suicide" drones and low-cost "decoy" drones, which tie up Ukrainian air defences.

"Unfortunately, there were hits to critical infrastructure facilities, and private and apartment buildings were damaged in several regions due to the massive drone attack," an air force statement said, adding that no casualties had been reported.

The attack damaged the power grid in Ternopil, a major city in western Ukraine, and cut power to around 70 percent of the region, governor Vyacheslav Nehoda said on national television.

Ternopil, some 220 km (134 miles) east of Nato-member Poland, and the surrounding region had a population of more than a million before the February 2022 Russian invasion, which drove many Ukrainians west.

"The consequences are bad because the facility was significantly affected and this will have impact on the power supply of the entire region for a long time," Nehoda said.

The attack also cut off water and disrupted heat supplies, the head of the regional defence headquarters Serhiy Nadal said via the Telegram messaging app.