KYIV, Ukraine (AP) — Russian drones blasted apartment buildings and the power grid in the southern Ukraine city of Odesa in an overnight attack that injured six people, including a toddler and two other children, officials said Wednesday.

Four apartment buildings were damaged in the bombardment, according to regional military administration head Oleh Kiper. Power company DTEK said two of its energy facilities suffered significant damage. The company said that 10 substations that distribute electricity in the Odesa region were damaged in December alone.

Russia has this year escalated its long-range attacks on urban areas of Ukraine. In recent months, as Russia's invasion of its neighbor approaches its four-year milestone in February, it has also intensified its targeting of energy infrastructure, seeking to deny Ukrainians heat and running water in the bitter winter months.

From January to November this year, more than 2,300 Ukrainian civilians were killed and more than 11,000 were injured, the United Nations said earlier this month. That was 26% higher than in the same period in 2024 and 70% higher than in 2023, it said.

Russia's sustained drone and missile attacks have taken place against backdrop of renewed diplomatic efforts to stop the fighting.

U.S. President Donald Trump hosted Ukrainian President Volodymyr Zelenskyy at his Florida resort on Sunday and announced that a settlement is "closer than ever before." The Ukrainian leader is due to hold talks next week with the heads of European governments supporting his efforts to secure acceptable terms.

The ongoing attacks, meantime, are inflaming tensions.

The overnight Odesa strikes "are further evidence of the enemy's terror tactics, which deliberately target civilian infrastructure," Kiper, the regional head, said.

Moscow has alleged that Ukraine attempted to attack Russian President Vladimir Putin's residence in northwestern Russia with 91 long-range drones late Sunday and early Monday. Ukrainian officials deny the claim and say it's a ruse to derail progress in the peace negotiations.

Maj. Gen. Alexander Romanenkov of the Russian air force claimed Wednesday that the drones took off from Ukraine's Sumy and Chernihiv regions.

At a briefing where no questions were allowed, he presented a map showing the drone flight routes before they were downed by Russian air defenses over the Bryansk, Tver, Smolensk and Novgorod regions.

It was not possible to independently verify the reports.

Ukraine's air force said Wednesday that Russia fired 127 drones at the country during the night, with 101 of them intercepted by air defenses.

Meanwhile, the Russian Defense Ministry said that 86 Ukrainian drones were shot down overnight over Russian regions, the Black Sea and the illegally annexed Crimea peninsula.

The Ukrainian attack started a fire at an oil refinery in Russia's southern Krasnodar region, but it was quickly put out, local authorities said.