Russia on Sunday launched a massive drone and missile attack on Ukraine, described by officials as the largest over the past months, targeting energy infrastructure and killing civilians.

The attack came as fears are mounting about Moscow’s intentions to devastate Ukraine’s power generation capacity ahead of the cold winter.

President Volodymyr Zelenskyy said that Russia had launched a total of 120 missiles and 90 drones in a large-scale attack across Ukraine. Various types of drones were deployed, he said, including Iranian-made Shaheds as well as cruise, ballistic and aircraft-launched ballistic missiles.

Ukrainian defenses shot down 140 air targets, Zelenskyy said in a statement on the Telegram messaging app.

“The enemy’s target was our energy infrastructure throughout Ukraine. Unfortunately, there is damage to objects from hits and falling debris. In Mykolaiv, as a result of a drone attack, two people were killed and six others were injured, including two children,” Zelenskyy said.

Two others were killed in the Odesa region, where the attack damaged energy infrastructure and disrupted power and water supplies, said local Gov. Oleh Kiper.

The combined drone and missile attack was the most powerful in three months, according to the head of Kyiv’s City Military Administration Serhii Popko.

Russian strikes have hammered Ukraine’s power infrastructure since Moscow’s all-out invasion of its neighbor in February 2022, prompting repeated emergency power shutdowns and nationwide rolling blackouts. Ukrainian officials have routinely urged Western allies to bolster the country’s air defenses to counter assaults and allow for repairs.

Explosions were heard across Ukraine on Sunday, including in the capital Kyiv, the key southern port of Odesa, as well as the country’s west and central regions, according to local reports.

The operational command of Poland’s armed forces wrote on X that Polish and allied aircraft, including fighter jets, have been mobilized in Polish airspace because of the “massive” Russian attack on neighboring Ukraine. The steps were aimed at providing safety in Poland’s border areas, it said.

One person was injured after the roof of a five-story residential building caught fire in Kyiv’s historic center, according to Popko.

A thermal power plant operated by private energy company DTEK was “seriously damaged,” the company said.