More than 100 Ukrainian drones were shot down over Russia Sunday, officials said, sparking a wildfire and setting an apartment block alight in one of the largest barrages seen over Russian skies since Moscow invaded Ukraine in February 2022.

Russia’s Ministry of Defense reported that it had shot down 125 drones overnight across seven regions. The southwestern region of Volgograd came under particularly heavy fire, with 67 Ukrainian drones reportedly downed by Russian air defenses.

Seventeen drones were also seen over Russia’s Voronezh region, where falling debris damaged an apartment block and a private home, said local governor Aleksandr Gusev. Images on social media showed flames rising from the windows of the top floor of a high-rise building. No casualties were reported.

A further 18 drones were reported over Russia’s Rostov region, where falling debris sparked a wildfire, said Gov. Vasily Golubev.

He said that the fire did not pose a threat to populated areas, but that emergency services were fighting to extinguish the blaze, which had engulfed 20 hectares (49.4 acres) of forest.

Meanwhile, 13 civilians were injured in an overnight barrage on the southern Ukrainian city of Zaporizhzhia Sunday after Ukrainian military leaders warned that Moscow could be preparing for a new military offensive in the country’s south.

The city was targeted by Russian guide bombs in 10 separate attacks that damaged a high-rise building and several residential homes, regional governor Ivan Fedorov wrote on his official Telegram channel. More people could still be trapped beneath the rubble, he said.

Ukrainian President Volodymyr Zelenskyy also said that the Zaporizhzhia attack had damaged the city’s transport links. “Today, Russia struck Zaporizhzhia with aerial bombs. Ordinary residential buildings were damaged and the entrance of one building was destroyed. The city’s infrastructure and railway were also damaged,” Zelenskyy said in a post on X, formerly Twitter.

“In total, 13 people were injured, and two were rescued from under the rubble. I thank all the emergency services for their rapid response and providing necessary assistance. The rubble clearing is still ongoing.”

The attacks come after the Ukrainian military warned Saturday that Russian forces may be preparing for offensive operations in the wider Zaporizhzhia region. Vladyslav Voloshyn, spokesperson for Ukraine’s southern military command, said that Russia was amassing personnel in this direction.

Ukraine’s air force also reported that 22 Russian drones were launched over the country overnight. It said that 15 were shot down in Ukraine’s Sumy, Vinnytsia, Mykolaiv, and Odesa regions, and that five more were destroyed using electronic defenses. The fate of the remaining two drones was not specified.