May 17 (UPI) — Hundreds of Ukrainian drones attacked the Moscow region overnight in what Russian officials called the largest attack in more than a year.

Russia’s state-run news agency Tass reported Sunday that at least three people died near the capital — a woman in her home in Khimki and two men in Mytishchi. The Indian Embassy in Russia said one of its citizens was among the dead and three were injured, CNN reported.

Moscow Mayor Sergey Sobyanin said 12 people were injured in attacks at an oil refinery in the city and at least one person was trapped under rubble. The Ukrainian Security Service said its forces also struck two oil pumping facilities.

The Russian military said it intercepted 556 drones during the blitz, the BBC reported. Drone fragments fell on a house in the village of Subbotino, causing it to catch fire and injure four people, Tass reported. More fragments fell on the Sheremetyevo Airport, though no one was injured there.

“The situation in the passenger terminals is cal,” a statement from airport officials said. “Sheremetyevo Airport is providing stable passenger and aircraft services.”

Ukrainian President Volodymyr Zelensky said Sunday that the drone attacks on Russia were “entirely justified” in response to Russia’s attacks on Ukraine.

Twenty-four people died in Kyiv, Ukraine, earlier this week in a Russian attack that included hundreds of missiles and drones. Another eight Ukrainians sustained injuries overnight in Russian shelling on the Dnipropetrovsk region.